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1.
ACS Appl Bio Mater ; 7(6): 3587-3604, 2024 Jun 17.
Article in English | MEDLINE | ID: mdl-38833534

ABSTRACT

Nature continually refines its processes for optimal efficiency, especially within biological systems. This article explores the collaborative efforts of researchers worldwide, aiming to mimic nature's efficiency by developing smarter and more effective nanoscale technologies and biomaterials. Recent advancements highlight progress and prospects in leveraging engineered nucleic acids and proteins for specific tasks, drawing inspiration from natural functions. The focus is developing improved methods for characterizing, understanding, and reprogramming these materials to perform user-defined functions, including personalized therapeutics, targeted drug delivery approaches, engineered scaffolds, and reconfigurable nanodevices. Contributions from academia, government agencies, biotech, and medical settings offer diverse perspectives, promising a comprehensive approach to broad nanobiotechnology objectives. Encompassing topics from mRNA vaccine design to programmable protein-based nanocomputing agents, this work provides insightful perspectives on the trajectory of nanobiotechnology toward a future of enhanced biomimicry and technological innovation.


Subject(s)
Biocompatible Materials , Nanotechnology , Biocompatible Materials/chemistry , Humans , Biotechnology , Drug Delivery Systems
2.
Bioresour Technol ; 400: 130697, 2024 May.
Article in English | MEDLINE | ID: mdl-38614145

ABSTRACT

Effects of a phosphorus-solubilizing bacteria (PSB) Bacillus megatherium on growth and lipid production of Chlorella sorokiniana were investigated in synthesized swine wastewater with dissolved inorganic phosphorus (DIP), insoluble inorganic phosphorus (IIP), and organic phosphorus (OP). The results showed that the PSB significantly promoted the algal growth in OP and IIP, by 1.10 and 1.78-fold, respectively. The algal lipid accumulation was also greatly triggered, respectively by 4.39, 1.68, and 1.38-fold in DIP, IIP, and OP. Moreover, compared with DIP, OP improved the oxidation stability of algal lipid by increasing the proportion of saturated fatty acids (43.8 % vs 27.9 %), while the PSB tended to adjust it to moderate ranges (30.2-41.6 %). Further, the transcriptome analysis verified the OP and/or PSB-induced up-regulated genes involving photosynthesis, lipid metabolism, signal transduction, etc. This study provided novel insights to enhance microalgae-based nutrient removal combined with biofuel production in practical wastewater, especially with complex forms of phosphorus.


Subject(s)
Chlorella , Lipids , Phosphates , Wastewater , Wastewater/microbiology , Animals , Chlorella/metabolism , Chlorella/growth & development , Swine , Phosphates/metabolism , Lipids/biosynthesis , Phosphorus/metabolism , Lipid Metabolism , Solubility , Bacillus/metabolism
3.
Heliyon ; 10(7): e28090, 2024 Apr 15.
Article in English | MEDLINE | ID: mdl-38571596

ABSTRACT

Background: Lung adenocarcinoma (LUAD) has a complex tumor heterogeneity. Our research attempts to clearness LUAD subtypes and build a reliable prognostic signature according to the activity changes of the hallmark and immunologic gene sets. Methods: According to The Cancer Genome Atlas (TCGA) - LUAD dataset, changes in marker and immune gene activity were analyzed, followed by identification of prognosis-related differential gene sets (DGSs) and their related LUAD subtypes. Survival analysis, correlation with clinical characteristics, and immune microenvironment assessment for subtypes were performed. Moreover, the differentially expressed genes (DEGs) between different subtypes were identified, followed by the construction of a prognostic risk score (RS) model and nomogram model. The tumor mutation burden (TMB) and tumor immune dysfunction and exclusion (TIDE) of different risk groups were compared. Results: Two LUAD subtypes were determined according to the activity changes of the hallmark and immunologic gene sets. Cluster 2 had worse prognosis, more advanced tumor and clinical stages than cluster 1. Moreover, a prognostic RS signature was established using two LUAD subtype-related DEGs, which could stratify patients at different risk levels. Nomogram model incorporated RS and clinical stage exerted good prognostic performance in LUAD patients. A shorter survival time and higher TMB were observed in the high-risk patients. Conclusions: Our findings revealed that our constructed prognostic signature could exactly predict the survival status of LUAD cases, which was helpful in predicting the prognosis and guiding personalized therapeutic strategies for LUAD.

4.
World J Hepatol ; 16(2): 229-240, 2024 Feb 27.
Article in English | MEDLINE | ID: mdl-38495269

ABSTRACT

BACKGROUND: Echinococcosis is prevalent in 9 provinces in Western and Northern China. An epidemiological survey of echinococcosis in 2012 and 2016 showed cases of echinococcosis in Yunnan Province. AIM: To understand the spatial distribution and epidemiological characteristics of echinococcosis in Yunnan for the prevention and control of echinococcosis and to reduce the risk of infection in Yunnan Province. METHODS: Based on the China Information System for Disease Control and Prevention (CISDCP), echinococcosis cases reported from 36 hospitals and 34 Centers for Disease Control were investigated and epidemiologically analyzed from 2021 to 2022. The exclusion criteria included suspected cases, same case only counted once and cases not from Yunnan. A total of 705 cases were investigated, of which 397 cases were suitable for statistical analysis. In these 397 cases, epidemiological investigation was tracked in 187 cases. All data were inputted using double entry in the Excel database, with error correction by double-entry comparison. The data on echinococcosis cases in Yunnan Province were analyzed by ArcGIS 10.1 software to generate a density map of echinococcosis distribution. All statistical analyses were conducted using SPSS 17.0, including the chi-square test, linear regression test and logistic univariate and multivariate regression analyses. RESULTS: A total of 397 cases were found in 89 counties in Yunnan Province. The number of cases in the top three prefectures were Dali (38.1%), Diqing (10.1%), and Kunming (8.3%), and the top five counties were Jianchuan (9.1%), Shangri La (8.3%), Eryuan (7. 6%), Heqing (6.9%), and Dali Districts (5.0%). There were significant differences between the different areas. The case reporting rate by CISDCP (33.8%) was low; the first case was reported by CISDCP in 2002, and the highest number of cases was 50 (2017). Confirmed and clinical cases accounted for 62.5% and 37.5%, respectively. However, 90.9% of the cases of hydatid disease were reported by the hospital system, and only 9.1% of the cases of hydatid disease were found in the community through active screening. The difference between the two methods of case detection was statistically significant. Most of the cases of echinococcosis were found in farmers/herdsmen (75.1%) and students (9.1%). In addition, Han (43.6%) and Bai (26.2%) had a higher incidence of infection than other nationalities, and the liver (87.7%) and lung (6.8%) were the most common sites of cyst formation. Among the analyzed cases, 187 were epidemiologically analyzed and the clinical symptoms were not obvious in the early stage in 47.1% of cases. The results of logistic regression analysis showed that the age group, education level, presence of dogs in the family (either previously or currently), and handwashing (occasionally or not) were factors related to echinococcosis infection. 55.6% of cases were in endemic areas, and 44.4% of cases were in non-endemic areas. Among 83 cases in non-endemic areas, only 4 cases had been to endemic areas and had a history of living, working, travelling, or hunting in echinococcosis epidemic areas. CONCLUSION: Cases of echinococcosis were reported throughout the entire Yunnan province, with the majority distributed in Western Yunnan, suggesting that echinococcosis control should be strengthened in this area. We suggest that an epidemiological investigation should be carried out in the future, based on the clues from newly discovered cases in hospitals or from the CISDCP. The newly discovered cases in the hospital provided clues to comprehensively determine the location of cases and where epidemic spot investigation should be conducted.

5.
Discov Oncol ; 15(1): 81, 2024 Mar 21.
Article in English | MEDLINE | ID: mdl-38512494

ABSTRACT

BACKGROUND: Post-hepatectomy liver failure (PHLF) is a serious complication after hepatectomy and a major cause of death. The current criteria for PHLF diagnosis (ISGLS consensus) require laboratory data of elevated INR level and hyperbilirubinemia on or after postoperative day 5. This study aims to propose a new indicator for the early clinical prediction of PHLF. METHODS: The peri-operative arterial lactate concentration level ratios were derived from time points within the 3 days before surgery and within POD1, the patients were divided into two groups: high lactate ratio group (≥ 1) and low lactate ratio group (< 1). We compared the differences in morbidity rates between the two groups. Utilized logistic regression analysis to identify the risk factors associated with PHLF development and ROC curves to compare the predictive value of lactate ratio and other liver function indicators for PHLF. RESULTS: A total of 203 patients were enrolled in the study. Overall morbidity and severe morbidity occurred in 64.5 and 12.8 per cent of patients respectively. 39 patients (19.2%) met the criteria for PHLF, including 15 patients (7.4%) with clinically relevant Post-hepatectomy liver failure (CR-PHLF). With a significantly higher incidence of PHLF observed in the lactate ratio ≥ 1 group compared to the lactate ratio < 1 group (n = 34, 26.8% vs. n = 5, 6.6%, P < 0.001). Multivariable logistic regression analysis revealed that a lactate ratio ≥ 1 was an independent predictor for PHLF (OR: 3.239, 95% CI 1.097-9.565, P = 0.033). Additionally, lactate ratio demonstrated good predictive efficacy for PHLF (AUC = 0.792). CONCLUSIONS: Early assessment of peri-operative arterial lactate concentration level ratios may provide experience in early intervention of complications in patients with hepatocellular carcinoma, which can reduce the likelihood of PHLF occurrence and improve patient prognosis.

6.
Front Immunol ; 15: 1343512, 2024.
Article in English | MEDLINE | ID: mdl-38533503

ABSTRACT

Background: Despite early attempts, the relationship between immune characteristics and gastrointestinal tract cancers remains incompletely elucidated. Hence, rigorous and further investigations in this domain hold significant clinical relevance for the development of novel potential immunotherapeutic targets. Methods: We conducted a two-sample Mendelian randomization (MR) analysis using the tools available in the "TwoSampleMR" R package. The GWAS data for these 731 immune traits were sourced from the GWAS Catalog database. Concurrently, data on gastrointestinal tract cancers, encompassing malignant tumors in the esophagus, stomach, small intestine, colon, and rectum, were extracted from the FinnGen database. The immune traits subjected to MR analysis predominantly fall into four categories: median fluorescence intensities (MFI), relative cell (RC), absolute cell (AC), and morphological parameters (MP). To ensure the reliability of our findings, sensitivity analyses were implemented to address robustness, account for heterogeneity, and alleviate the impact of horizontal pleiotropy. Results: A total of 78 immune traits causally linked to gastrointestinal tract cancers were identified, encompassing esophageal cancer (12 traits), gastric cancer (13 traits), small intestine cancer (22 traits), colon cancer (12 traits), and rectal cancer (19 traits). Additionally, 60 immune traits were recognized as protective factors associated with gastrointestinal tract cancers, distributed across esophageal cancer (14 traits), gastric cancer (16 traits), small intestine cancer (7 traits), colon cancer (14 traits), and rectal cancer (9 traits). Furthermore, it was observed that seven immune traits are causally related to gastrointestinal tract cancers in at least two locations. These traits include "CCR2 on CD14- CD16+ monocyte," "CD19 on IgD+ CD38-," "CD19 on IgD+ CD38- naive," "CD25hi CD45RA+ CD4 not Treg AC," "CD27 on unsw mem," "CD28 on CD39+ activated Treg," and "CD45 on CD4+." Conclusion: This study elucidates a causal link between immune cells and gastrointestinal tract cancers at various sites through genetic investigation. The findings of this research open up new perspectives and resources for exploring tumor prevention strategies and immunotherapeutic targets.


Subject(s)
Colonic Neoplasms , Esophageal Neoplasms , Gastrointestinal Neoplasms , Rectal Neoplasms , Stomach Neoplasms , Humans , Mendelian Randomization Analysis , Reproducibility of Results
7.
Nat Chem Biol ; 20(4): 406-407, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38467845
8.
J Nat Prod ; 87(3): 583-590, 2024 Mar 22.
Article in English | MEDLINE | ID: mdl-38414352

ABSTRACT

Treatment of 27-O-acetylwithaferin A (2) with the non-nucleophilic base, 1,8-diazabicyclo[5,4,0]undec-7-ene (DBU), afforded 5ß,6ß-epoxy-4ß-hydroxy-1-oxo-witha-2(3),23(24),25(27)-trienolide (3) and 4, a homodimer of withaferin A resulting from a Diels-Alder [4 + 2] type cycloaddition of the intermediate α,ß-dimethylene-δ-lactone (9). Structures of 3 and 4 were elucidated using HRMS and 1D and 2D NMR spectroscopic data. The structure of 4 was also confirmed by single crystal X-ray crystallographic analysis of its bis-4-O-p-nitrobenzoate (8). Formation of withaferin A homodimer (4) as the major product suggests regio- and stereoselectivity of the Diels-Alder [4 + 2] cycloaddition reaction of 9. Acetylation of 2-4 afforded their acetyl derivatives 5-7, respectively. Compounds 2-4 and 6-8 were evaluated for their cytotoxic activities against four prostate cancer (PC) cell lines (LNCaP, 22Rv1, DU-145, and PC-3) and normal human foreskin fibroblast (HFF) cells. Significantly, 4 exhibited improved activity compared to the other compounds for most of the tested cell lines.


Subject(s)
Acetic Acid , Withanolides , Male , Humans , Cycloaddition Reaction , Withanolides/pharmacology , Withanolides/chemistry , Magnetic Resonance Spectroscopy , Molecular Structure
9.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 32(1): 297-301, 2024 Feb.
Article in Chinese | MEDLINE | ID: mdl-38387938

ABSTRACT

Multiple myeloma (MM) is a hematologic neoplasm characterized by malignant proliferation of monoclonal plasma cells in the bone marrow. NK cells, a class of innate lymphocytes with potent natural killer activity, are capable of recognizing and destroying tumor cells and virally infected cells, and have attracted attention as a potential anticancer therapy. In patients with MM, NK cells are suppressed in number and function, resulting in reduced immune surveillance and clearance of myeloma cells. Restoring or enhancing the killing effect of NK cells on myeloma cells is an important strategy for MM immunotherapy, and some progress has been made in clinical trials targeting NK cellrelated therapies. This article reviews the research progress on the applications prospects of NK cell in MM immunotherapy.


Subject(s)
Multiple Myeloma , Humans , Bone Marrow/pathology , Cell- and Tissue-Based Therapy , Immunotherapy , Immunotherapy, Adoptive , Killer Cells, Natural , Multiple Myeloma/pathology
10.
Chem Commun (Camb) ; 60(19): 2633-2636, 2024 Feb 29.
Article in English | MEDLINE | ID: mdl-38345643

ABSTRACT

We explore an uncommon ultrasonic reduction method to exsolute Ag from perovskite La0.87Ag0.03FeO3-δ, forming a composite with enhanced catalytic oxidation activity. Such a mild exsolution is based on the coupling effect of ultrasonic cavitation and reducible BH4-, and holds great potential in the fields of energy and environment catalysis.

11.
Science ; 383(6684): 750-756, 2024 Feb 16.
Article in English | MEDLINE | ID: mdl-38359135

ABSTRACT

Water can accelerate a variety of organic reactions far beyond the rates observed in classical organic solvents. However, using pure water as a solvent introduces solubility constraints that have limited the applicability of efficient photochemistry in particular. We report here the formation of aggregates between pairs of arenes, heteroarenes, enamines, or esters with different electron affinities in an aqueous medium, leading to an oil-water phase boundary through substrate melting point depression. The active hydrogen atoms in the reactants engage in hydrogen bonds with water, thereby accelerating photochemical reactions. This methodology realizes appealingly simple conditions for aqueous coupling reactions of complex solid molecules, including complex drug molecules that are poorly soluble in water.

12.
J Am Chem Soc ; 146(9): 6189-6198, 2024 Mar 06.
Article in English | MEDLINE | ID: mdl-38386630

ABSTRACT

Polyketides with the isochroman-3-one pharmacophore are rare among fungal natural products as their biosynthesis requires an unorthodox S-type aromatic ring cyclization. Genome mining uncovered a conserved gene cluster in select leotiomycetous fungi that encodes the biosynthesis of cytosporones, including isochroman-3-one congeners. Combinatorial biosynthesis in total biosynthetic and biocatalytic formats in Saccharomyces cerevisiae and in vitro reconstitution of key reactions with purified enzymes revealed how cytosporone structural and bioactivity diversity is generated. The S-type acyl dihydroxyphenylacetic acid (ADA) core of cytosporones is assembled by a collaborating polyketide synthase pair. Thioesterase domain-catalyzed transesterification releases ADA esters, some of which are known Nur77 modulators. Alternatively, hydrolytic release allows C6 hydroxylation by a flavin-dependent monooxygenase, yielding a trihydroxybenzene moiety. Reduction of the C9 carbonyl by a short chain dehydrogenase/reductase initiates isochroman-3-one formation, affording cytosporones with cytotoxic and antimicrobial activity. Enoyl di- or trihydroxyphenylacetic acids are generated as shunt products, while isocroman-3,4-diones are formed by autoxidation. The cytosporone pathway offers novel polyketide biosynthetic enzymes for combinatorial synthetic biology to advance the production of "unnatural" natural products for drug discovery.


Subject(s)
Biological Products , Polyketides , Fungi/genetics , Saccharomyces cerevisiae/metabolism , Polyketide Synthases/metabolism , Polyketides/chemistry , Biological Products/metabolism
13.
Osteoporos Int ; 35(1): 53-67, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37698600

ABSTRACT

We examined the performance of an intelligent fracture liaison service (FLS) assisted by digital health (DH) to reduce all-cause mortality (ACM) risk. According to our findings, the new FLS reduced ACM by 36%. INTRODUCTION: A well-designed secondary prevention program known as FLS enhances the bone densitometry-based assessment rate as well as osteoporosis (OP) medication usage following a fracture. However, there are only a few reports on FLS incorporating DH, and it remains unclear whether this integration has influenced patient ACM, which refers to the overall death rate from any cause during the study period. METHODS: This retrospective observational study was conducted on data from the Fragility Fracture Registration System database linked to the Regional Health Registration Platform of Kunshan City and the Population Death Registration System of Jiangsu Province for one tertiary-level A hospital in China. Patients aged ≥ 50 years, who experienced an OP fracture between January 1, 2017, and July 27, 2022, requiring hospitalization, were selected for analysis. We compared the outcomes of patients who received routine fragility fracture management (the no-FLS group) or FLS (the FLS group). We employed multivariable Cox regression with inverse probability weighting based on the propensity score (PS). RESULTS: Of 2317 patients, 756 (32.6%) received FLS and 1561 (67.4%) did not. Using PS matching, we minimized the baseline characteristic differences between the two groups in the propensity score-matched samples, relative to the unmatched samples. Based on our analysis, the new FLS reduced ACM by 36% (hazard ratio [HR], 0.64; 95% confidence interval [CI], 0.47 to 0.87; P-value = 0.004). Moreover, FLS patients experienced further reductions in fall-related mortality, refracture rate, and total refracture-related hospital costs, and had increased dual-energy X-ray absorptiometry (DXA) testing and treatment initiation rates, relative to the no-FLS patients. CONCLUSIONS: A new FLS model implementation assisted by DH can effectively reduce ACM among elderly patients with OP fractures requiring surgery. In future investigations, we recommend examining the scalability of this model.


Subject(s)
Bone Density Conservation Agents , Osteoporosis , Osteoporotic Fractures , Aged , Humans , Osteoporotic Fractures/epidemiology , Digital Health , Bone Density Conservation Agents/therapeutic use , Osteoporosis/drug therapy , Osteoporosis/epidemiology , Absorptiometry, Photon , Secondary Prevention
14.
Int J Biol Macromol ; 254(Pt 3): 127971, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37944720

ABSTRACT

Developing efficient and safe antibacterial agents to inhibit pathogens including Physalospora piricola and Staphylococcus aureus is of great importance. Herein, a novel compound composed of Rosa roxburghii procyanidin, chitosan and selenium nanoparticle (RC-SeNP) was bio-synthesized, with the average diameter and zeta potential being 84.56 nm and -25.60 mV, respectively. The inhibition diameter of the RC-SeNP against P. piricola and S. aureus reached 18.67 mm and 13.13 mm, and the maximum scavenging activity against DPPH and ABTS reached 96.02% and 98.92%, respectively. Moreover, the RC-SeNP completely inhibited the propagation P. piricola and S. aureus on actual apples, suggesting excellent in vivo antimicrobial capacity. The transcriptome analysis and electron microscope observation indicated that the antibacterial activity would be attributed to adhering to and crack the cell walls as well as damage the cytomembrane and nucleus. Moreover, the RC-SeNP effectively maintained the vitamin C, total acid, and water contents of red bayberry, demonstrating potential application for fruit preservation. At last, the RC-SeNP showed no cell toxicity and trace selenium residual dose (0.03 mg/kg on apple, 0.12 mg/kg on red bayberry). This study would enlighten future development on novel nano-bioantibacterial agents for sustainable agriculture.


Subject(s)
Chitosan , Nanoparticles , Rosa , Selenium , Antioxidants/pharmacology , Antioxidants/chemistry , Selenium/chemistry , Chitosan/chemistry , Staphylococcus aureus , Nanoparticles/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Plant Extracts/pharmacology
15.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 31(6): 1885-1889, 2023 Dec.
Article in Chinese | MEDLINE | ID: mdl-38071077

ABSTRACT

Cancer-associated fibroblasts (CAF) are a key component of the tumor microenvironment, which can secrete a variety of cytokines, chemokines and growth factors, directly and indirectly support cancer cells, also alter the immune cellular environment by inhibiting the activity of immune effector cells and recruiting immunosuppressive cells, thereby allowing cancer cells to evade immune surveillance. CAF has been proven to be associated with the development, progression, and poor prognosis of solid tumors. However, the role of CAF in hematological malignancies is still unclear. This article reviews the research progress of CAF in hematological malignancies.


Subject(s)
Cancer-Associated Fibroblasts , Hematologic Neoplasms , Neoplasms , Humans , Cancer-Associated Fibroblasts/metabolism , Cancer-Associated Fibroblasts/pathology , Neoplasms/metabolism , Hematologic Neoplasms/metabolism , Tumor Microenvironment , Fibroblasts/pathology
16.
bioRxiv ; 2023 Dec 10.
Article in English | MEDLINE | ID: mdl-38106193

ABSTRACT

Human mitochondrial tRNAs (mt-tRNAs), critical for mitochondrial biogenesis, are frequently associated with pathogenic mutations. These mt-tRNAs have unusual sequence motifs and require post-transcriptional modifications to stabilize their fragile structures. However, whether a modification that stabilizes a wild-type (WT) mt-tRNA structure would also stabilize its pathogenic variants is unknown. Here we show that the N 1 -methylation of guanosine at position 9 (m 1 G9) of mt-Leu(UAA), while stabilizing the WT tRNA, has an opposite and destabilizing effect on variants associated with MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes). This differential effect is further demonstrated by the observation that demethylation of m 1 G9, while damaging to the WT tRNA, is beneficial to the major pathogenic variant, improving its structure and activity. These results have new therapeutic implications, suggesting that the N 1 -methylation of mt-tRNAs at position 9 is a determinant of pathogenicity and that controlling the methylation level is an important modulator of mt-tRNA-associated diseases.

17.
bioRxiv ; 2023 Dec 09.
Article in English | MEDLINE | ID: mdl-38106225

ABSTRACT

Monitoring the dynamic changes of cellular tRNA pools is challenging, due to the extensive post-transcriptional modifications of individual species. The most critical component in tRNAseq is a processive reverse transcriptase (RT) that can read through each modification with high efficiency. Here we show that the recently developed group-II intron RT Induro has the processivity and efficiency necessary to profile tRNA dynamics. Using our Induro-tRNAseq, simpler and more comprehensive than the best methods to date, we show that Induro progressively increases readthrough of tRNA over time and that the mechanism of increase is selective removal of RT stops, without altering the misincorporation frequency. We provide a parallel dataset of the misincorporation profile of Induro relative to the related TGIRT RT to facilitate the prediction of non-annotated modifications. We report an unexpected modification profile among human proline isoacceptors, absent from mouse and lower eukaryotes, that indicates new biology of decoding proline codons.

18.
J Am Chem Soc ; 145(48): 26452-26462, 2023 12 06.
Article in English | MEDLINE | ID: mdl-37976043

ABSTRACT

Postsynthetic diversification of peptides through selective modification of endogenous amino acid side chains has enabled significant advances in peptide drug discovery while expanding the biological and medical chemistry space. However, current tools have been focused on the modification of reactive polar and ionizable side chains, whereas the decoration of aromatic systems (e.g., the N(in) of the tryptophan) has been a long-standing challenge. Here, we introduce metallaphotocatalysis in solid-phase peptide synthesis for the on-resin orthogonal N-arylation of relevant tryptophan-containing peptides. The protocol allows the chemoselective introduction of a new C(sp2)-N bond at the N(in) of tryptophan in biologically active protected peptide sequences in the presence of native redox-sensitive side chains. The fusion of metallaphotocatalysis with solid-phase peptide synthesis opens new perspectives in diversifying native amino acid side chains.


Subject(s)
Peptides , Tryptophan , Tryptophan/chemistry , Peptides/chemistry , Amino Acids/chemistry , Oxidation-Reduction , Solid-Phase Synthesis Techniques
19.
Methods Enzymol ; 692: 127-153, 2023.
Article in English | MEDLINE | ID: mdl-37925177

ABSTRACT

Synthesis of RNA standards that contain an internal site-specific modification is important for mapping and quantification of the modified nucleotide in sequencing analysis. While RNA containing a site-specific modification can be readily synthesized by solid-state coupling for less than 100-mer nucleotides, longer RNA must be synthesized by enzymatic ligation in the presence of a DNA splint. However, long RNAs have structural heterogeneity, and those generated by in vitro transcription have 3'-end sequence heterogeneity, which together substantially reduce the yield of ligation. Here we describe a method of 3-part splint ligation that joins an in vitro transcribed left-arm RNA, an in vitro transcribed right-arm RNA, and a chemically synthesized modification-containing middle RNA, with an efficiency higher than previously reported. We report that the improved efficiency is largely attributed to the inclusion of a pair of DNA disruptors proximal to the ligation sites, and to a lesser extent to the homogeneous processing of the 3'-end of the left-arm RNA. The yields of the ligated long RNA are sufficiently high to afford purification to homogeneity for practical RNA research. We also verify the sequence accuracy at each ligation junction by nanopore sequencing.


Subject(s)
DNA , RNA , RNA/genetics , RNA/chemistry , Pseudouridine
20.
J Transl Med ; 21(1): 702, 2023 10 09.
Article in English | MEDLINE | ID: mdl-37814317

ABSTRACT

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is characterised by limited responses to chemoimmunotherapy attributed to highly desmoplastic tumor microenvironment. Disrupting the tumor-stromal cell crosstalk is considered as an improved PDAC treatment strategy, whereas little progress has been made due to poor understanding of its underlying mechanism. Here, we examined the cellular role of melanoma associated antigen A isoforms (MAGEA) in regulating tumor-stromal crosstalk mediated chemoresistance. METHODS: We used clinical samples to explore the correlation between MAGEA expression and patient prognosis in multiple cancers. We utilized cancer cell lines, patient derived organoids and orthotopic PDAC model to examine the function of MAGEA in chemoresistance. We performed biochemical, proteome profiler array and transcriptional analysis to uncover a mechanism that governs tumor-stromal crosstalk. We developed a multi-MAGEA antigen targeted DNA vaccine and tested its effect on PDAC tumor growth. RESULTS: We establish MAGEA as a regulator of the tumor-stromal crosstalk in PDAC. We provide strong clinical evidence indicating that high MAGEA expression, including MAGEA2, MAGEA3 and MAGEA10, correlates with worse chemotherapeutic response and poor prognosis in multiple cancers, while their expression is up-regulated in chemoresistant PDAC patient derived organoids and cancer cell lines. Mechanistically, MAGEA2 prohibits gemcitabine-induced JNK-c-Jun-p53 mediated cancer cell apoptosis, while gemcitabine stimulated pancreatic stellate cells secretes GDF15 to further enhance the gemcitabine resistance of MAGEA2 expressing cells by activating GFRAL-RET mediated Akt and ERK1/2 dependent survival pathway. Strikingly, immunization with a DNA vaccine that targeting multiple MAGEA antigens, including MAGEA2, MAGEA3 and MAGEA10, elicits robust immune responses against the growth of gemcitabine resistant tumors. CONCLUSIONS: These findings suggest that targeting MAGEA-mediated paracrine regulation of chemoresistance by immunotherapy can be an improved pancreatic cancer treatment strategy.


Subject(s)
Carcinoma, Pancreatic Ductal , Pancreatic Neoplasms , Vaccines, DNA , Humans , Vaccines, DNA/metabolism , Vaccines, DNA/pharmacology , Vaccines, DNA/therapeutic use , Deoxycytidine/pharmacology , Cell Line, Tumor , Pancreatic Neoplasms/pathology , Gemcitabine , Carcinoma, Pancreatic Ductal/drug therapy , Carcinoma, Pancreatic Ductal/genetics , Immunization , Stromal Cells/pathology , Drug Resistance, Neoplasm , Tumor Microenvironment , Pancreatic Neoplasms
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