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1.
J Am Chem Soc ; 146(28): 18817-18822, 2024 Jul 17.
Article in English | MEDLINE | ID: mdl-38968608

ABSTRACT

NAD(H)-dependent enzymes play a crucial role in the biosynthesis of pharmaceuticals and fine chemicals, but the limited recyclability of the NAD(H) cofactor hinders its more general application. Here, we report the generation of mechano-responsive PEI-modified Cry3Aa protein crystals and their use for NADH recycling over multiple reaction cycles. For demonstration of its practical utility, a complementary Cry3Aa protein particle containing genetically encoded and co-immobilized formate dehydrogenase for NADH regeneration and leucine dehydrogenase for catalyzing the NADH-dependent l-tert-leucine (l-tert-Leu) biosynthesis has been produced. When combined with the PEI-modified Cry3Aa crystal, the resultant reaction system could be used for the efficient biosynthesis of l-tert-Leu for up to 21 days with a 10.5-fold improvement in the NADH turnover number.


Subject(s)
Formate Dehydrogenases , NAD , NAD/metabolism , NAD/chemistry , Formate Dehydrogenases/metabolism , Formate Dehydrogenases/chemistry , Leucine Dehydrogenase/metabolism , Leucine Dehydrogenase/chemistry , Crystallization , Enzymes, Immobilized/chemistry , Enzymes, Immobilized/metabolism , Models, Molecular
2.
Adv Sci (Weinh) ; 10(30): e2301724, 2023 10.
Article in English | MEDLINE | ID: mdl-37675807

ABSTRACT

Helicobacter pylori (H. pylori) causes infection in the stomach and is a major factor for gastric carcinogenesis. The application of antimicrobial peptides (AMPs) as an alternative treatment to traditional antibiotics is limited by their facile degradation in the stomach, their poor penetration of the gastric mucosa, and the cost of peptide production. Here, the design and characterization of a genetically encoded H. pylori-responsive microbicidal protein crystal Cry3Aa-MIIA-AMP-P17 is described. This designed crystal exhibits preferential binding to H. pylori, and when activated, promotes the targeted release of the AMP at the H. pylori infection site. Significantly, when the activated Cry3Aa-MIIA-AMP-P17 crystals are orally delivered to infected mice, the Cry3Aa crystal framework protects its cargo AMP against degradation, resulting in enhanced in vivo efficacy against H. pylori infection. Notably, in contrast to antibiotics, treatment with the activated crystals results in minimal perturbation of the mouse gut microbiota. These results demonstrate that engineered Cry3Aa crystals can serve as an effective platform for the oral delivery of therapeutic peptides to treat gastrointestinal diseases.


Subject(s)
Helicobacter Infections , Helicobacter pylori , Animals , Mice , Helicobacter Infections/drug therapy , Helicobacter Infections/metabolism , Stomach , Gastric Mucosa/metabolism , Anti-Bacterial Agents
3.
J Am Chem Soc ; 145(18): 10249-10258, 2023 05 10.
Article in English | MEDLINE | ID: mdl-37125745

ABSTRACT

Macrocyclization has been touted as an effective strategy to enhance the in vivo stability and efficacy of protein therapeutics. Herein, we describe a scalable and robust system based on the endogenous biosynthesis of a noncanonical amino acid coupled to the pyrrolysine translational machinery for the generation of lasso-grafted proteins. The in cellulo biosynthesis of the noncanonical amino acid d-Cys-ε-Lys was achieved by hijacking the pyrrolysine biosynthesis pathway, and then, its genetical incorporation into proteins was performed using an optimized PylRS/tRNAPyl pair and cell line. This system was then applied to the structurally inspired cyclization of a 23-mer therapeutic P16 peptide engrafted on a fusion protein, resulting in near-complete cyclization of the target cyclic subunit in under 3 h. The resulting cyclic P16 peptide fusion protein possessed much higher CDK4 binding affinity than its linear counterpart. Furthermore, a bifunctional bicyclic protein harboring a cyclic cancer cell targeting RGD motif on the one end and the cyclic P16 peptide on the other is produced and shown to be a potent cell cycle arrestor with improved serum stability.


Subject(s)
Amino Acids , Amino Acyl-tRNA Synthetases , Amino Acids/metabolism , Amino Acyl-tRNA Synthetases/metabolism , Proteins/metabolism , Protein Biosynthesis , Peptides/metabolism
4.
Article in English | MEDLINE | ID: mdl-33685890

ABSTRACT

We have designed, synthesized, and characterized a library of 38 novel flavonoid compounds linked with amines. Some of these amine-linked flavonoids have potent in vitro activity against parasites that cause cutaneous leishmaniasis, a tropical disease endemic in 80 countries worldwide. The most promising candidate, FM09h, was highly active with IC50 of 0.3 µM against L. amazonensis, L. tropica and L. braziliensis amastigotes. It was metabolically stable (39% and 66% of FM09h remaining after 30-minute incubation with human and rat liver microsomes respectively). In L. amazonensis LV78 cutaneous leishmaniasis mouse model, intralesional injection of FM09h (10 mg/kg, once every 4 days for 8 times) demonstrated promising effect in reducing the footpad lesion thickness by 72%, displaying an efficacy comparable to SSG (63%).

5.
Toxins (Basel) ; 14(12)2022 11 23.
Article in English | MEDLINE | ID: mdl-36548720

ABSTRACT

The crystal protein Cry5B, a pore-forming protein produced by the soil bacterium Bacillus thuringiensis, has been demonstrated to have excellent anthelmintic activity. While a previous structure of the three-domain core region of Cry5B(112-698) had been reported, this structure lacked a key N-terminal extension critical to function. Here we report the structure of Cry5B(27-698) containing this N-terminal extension. This new structure adopts a distinct quaternary structure compared to the previous Cry5B(112-698) structure, and also exhibits a change in the conformation of residues 112-140 involved in linking the N-terminal extension to the three-domain core by forming a random coil and an extended α-helix. A role for the N-terminal extension is suggested based on a computational model of the tetramer with the conformation of residues 112-140 in its alternate α-helix conformation. Finally, based on the Cry5B(27-698) structure, site-directed mutagenesis studies were performed on Tyr495, which revealed that having an aromatic group or bulky group at this residue 495 is important for Cry5B toxicity.


Subject(s)
Bacillus thuringiensis , Bacillus thuringiensis/metabolism , Endotoxins/metabolism , Bacillus thuringiensis Toxins/metabolism , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Hemolysin Proteins/metabolism
6.
J Immunother Cancer ; 10(9)2022 09.
Article in English | MEDLINE | ID: mdl-36104100

ABSTRACT

BACKGROUND: Although immune checkpoint inhibitors (ICIs) have been shown to yield promising therapeutic outcomes in a small subset of patients with triple negative breast cancer (TNBC), the majority of patients either do not respond or subsequently develop resistance. Recent studies have revealed the critical role of TP53 gene in cancer immunology. Loss or mutation of p53 in cancer cells has been found to promote their immune escape. Given the high mutation frequency of TP53 in TNBC cells, restoration of p53 function could be a potential strategy to overcome their resistance to anti-programmed cell death protein 1 (PD-1)/programmed cell death ligand 1 (PD-L1) therapy. Herein, we have assessed the use of Pos3Aa crystal-based platform to mediate the intracellular delivery of p53 protein to restore p53 activity in p53 null tumors and consequently augment anti-PD-1 activity. METHODS: The efficiency of Pos3Aa-p53 crystals in delivering p53 protein was evaluated using confocal imaging, immunofluorescence staining, flow cytometry and RNA-seq. The ability of Pos3Aa-p53 crystals to remodel tumor microenvironment was investigated by examining the markers of immunogenic cell death (ICD) and the expression of PD-L1, indoleamine 2,3-dioxygenase 1, tryptophan 2,3-dioxygenase 2 and type I interferon (IFN). Finally, both unilateral and bilateral 4T1 tumor mouse models were utilized to assess the efficacy of Pos3Aa-p53 crystal-mediated p53 restoration in enhancing the antitumor activity of ICIs. T cells in tumor tissues and spleens were analyzed, and the in vivo biosafety of the Pos3Aa-p53 crystal/anti-PD-1 antibody combination was also evaluated. RESULTS: Delivery of p53 protein into p53-null TNBC 4T1 cells via Pos3Aa-p53 crystals restored the p53 activity, and therefore led to the induction of ICD, activation of type I IFN signaling and upregulation of PD-L1 expression. Pos3Aa-p53 crystals significantly enhanced T cell infiltration and activation in 4T1 tumors, thereby sensitizing them to anti-PD-1 therapy. The combination of Pos3Aa-p53 crystals with anti-PD-1 antibody also induced a systemic antitumor immunity resulting in the inhibition of distal tumor growth with minimal toxicity. CONCLUSION: This study validates that p53 restoration can be an effective approach to overcome ICI resistance and demonstrates that intracellular delivery of p53 protein can be an efficient, safe and potentially universal strategy to restore p53 activity in tumors carrying TP53 mutation.


Subject(s)
Triple Negative Breast Neoplasms , Animals , B7-H1 Antigen/metabolism , Genes, p53 , Humans , Immunologic Factors/therapeutic use , Immunotherapy/methods , Mice , Triple Negative Breast Neoplasms/pathology , Tumor Microenvironment , Tumor Suppressor Protein p53/genetics
7.
Acta Biomater ; 135: 582-592, 2021 11.
Article in English | MEDLINE | ID: mdl-34496285

ABSTRACT

The tumor suppressor p16 protein is an endogenous CDK4/6 inhibitor. Inactivation of its encoding gene is found in nearly half of human cancers. Restoration of p16 function via adenovirus-based gene delivery has been shown to be effective in suppressing aberrant cell growth in many types of cancer, however, the potential risk of insertional mutagenesis in genomic DNA remains a major concern. Thus, there has been great interest in developing efficient strategies to directly deliver proteins into cells as an alternative that can avoid such safety concerns while achieving a comparable therapeutic effect. Nevertheless, intracellular delivery of protein therapeutics remains a challenge. Our group has recently developed a protein delivery platform based on an engineered Pos3Aa protein that forms sub-micrometer-sized crystals in Bacillus thuringiensis cells. In this report, we describe the further development of this platform (Pos3AaTM) via rationally designed site-directed mutagenesis, and its resultant potency for the delivery of cargo proteins into cells. Pos3AaTM-based fusion protein crystals are shown to exhibit improved release of their cargo proteins as demonstrated using a model mCherry protein. Importantly, this Pos3AaTM platform is able to mediate the efficient intracellular delivery of p16 protein with significant endosomal escape, resulting in p16-mediated inhibition of CDK4/6 kinase activity and Rb phosphorylation, and as a consequence, significant cell cycle arrest and cell growth inhibition. These results validate the ability of these improved Pos3AaTM crystals to mediate enhanced cytosolic protein delivery and highlight the potential of using protein therapeutics as selective CDK4/6 inhibitors for cancer therapy. STATEMENT OF SIGNIFICANCE: Cytosolic delivery of bioactive therapeutic proteins capable of eliciting therapeutic benefit remains a significant challenge. We have previously developed a protein delivery platform based on engineered Pos3Aa protein crystals with excellent cell-permeability and endosomal escape properties. In this report, we describe the rational design of an improved Pos3Aa triple mutant (Pos3AaTM) with enhanced cargo release. We demonstrate that Pos3AaTM-mCherry-p16 fusion crystals can efficiently deliver p16 protein, a CDK4/6 inhibitor frequently inactivated in human cancers, into p16-deficient UM-SCC-22A cells, where it promotes significant G1 cell cycle arrest and cell growth inhibition. These results highlight the ability of the Pos3AaTM platform to promote potent cytosolic delivery of protein therapeutics, and the efficacy of p16 protein delivery as an effective strategy for treating cancer.


Subject(s)
Cyclin-Dependent Kinase Inhibitor p16 , Neoplasms , Cell Cycle , Cyclin-Dependent Kinase 4 , Humans , Tumor Suppressor Proteins
8.
Lab Chip ; 21(11): 2121-2128, 2021 06 01.
Article in English | MEDLINE | ID: mdl-34002198

ABSTRACT

Red blood cells (RBCs) are attractive carriers of biomolecular payloads due to their biocompatibility and the ability to shelter their encapsulated cargo. Commonly employed strategies to encapsulate payloads into RBCs, such as hypotonic shock, membrane fusion or electroporation, often suffer from low throughput and unrecoverable membrane impairment. This work describes an investigation of a method to encapsulate protein payloads into RBCs by controlling membrane deformation either transiently or extendedly in a microfluidic channel. Under the optimized conditions, the loading efficiency of enhanced green fluorescent protein into mouse RBCs increased was about 2.5- and 4-fold compared to that with osmotic entrapment using transient and extended deformation, respectively. Significantly, mouse RBCs loaded with human arginase exhibit higher enzymatic activity and membrane integrity compared to their counterparts loaded by osmotic entrapment. These features together with the fact that this shear-mediated encapsulation strategy allows loading with physiological buffers highlight the key advantages of this approach compared to traditional osmotic entrapment.


Subject(s)
Erythrocytes , Proteins , Microfluidics
9.
Biomaterials ; 271: 120759, 2021 04.
Article in English | MEDLINE | ID: mdl-33798968

ABSTRACT

Direct delivery of proteins into cells holds significant potential for basic research and drug development. However, the poor endosomal escape of conventional delivery strategies remains a challenge, thus limiting the clinical translation of many protein therapeutics. Herein, we report that engineered Cry3Aa protein (Pos3Aa) crystals formed naturally within Bacillus thuringiensis can serve as a vehicle for efficient cytosolic delivery of bioactive proteins. We showed that Pos3Aa-mediated delivery of tumor suppressor p53 protein, a promising therapeutic candidate found to be inactivated in nearly half of human cancers, resulted in the restoration of p53 function in p53-deficient cancer cells, and thereby sensitized them to 5-fluorouracil chemotherapy as demonstrated in in vitro and in vivo models. Our results validate that Pos3Aa crystals can be a robust and effective platform for the cytosolic delivery of effector proteins, and suggest that efficient uptake and endosomal escape could be critical for efficacious p53 protein-based cancer therapy.


Subject(s)
Neoplasms , Tumor Suppressor Protein p53 , Endosomes , Humans , Tumor Suppressor Protein p53/genetics
10.
Cell Chem Biol ; 28(2): 180-190.e6, 2021 02 18.
Article in English | MEDLINE | ID: mdl-33444530

ABSTRACT

The accumulation of α-synuclein amyloid fibrils in the brain is linked to Parkinson's disease and other synucleinopathies. The intermediate species in the early aggregation phase of α-synuclein are involved in the emergence of amyloid toxicity and considered to be the most neurotoxic. The N-terminal region flanking the non-amyloid-ß component domain of α-synuclein has been implicated in modulating its aggregation. Herein, we report the development of a SUMO1-derived peptide inhibitor (SUMO1(15-55)), which targets two SUMO-interacting motifs (SIMs) within this aggregation-regulating region and suppresses α-synuclein aggregation. Molecular modeling, site-directed mutagenesis, and binding studies are used to elucidate the mode of interaction, namely, via the binding of either of the two SIM sequences on α-synuclein to a putative hydrophobic binding groove on SUMO1(15-55). Subsequent studies show that SUMO1(15-55) also reduces α-synuclein-induced cytotoxicity in cell-based and Drosophila disease models.


Subject(s)
Peptides/chemistry , Peptides/pharmacology , Protein Aggregates/drug effects , SUMO-1 Protein/chemistry , SUMO-1 Protein/pharmacology , alpha-Synuclein/metabolism , Animals , Disease Models, Animal , Drosophila , Drug Discovery , Humans , Parkinson Disease/drug therapy , Parkinson Disease/metabolism , Peptides/metabolism , Protein Aggregation, Pathological/drug therapy , Protein Aggregation, Pathological/metabolism , Protein Interaction Maps/drug effects , SUMO-1 Protein/metabolism
11.
iScience ; 23(6): 101158, 2020 Jun 26.
Article in English | MEDLINE | ID: mdl-32464594

ABSTRACT

The effectiveness of cancer radiotherapy is frequently hindered by the hypoxia of the tumor microenvironment. Direct delivery of oxygen to hypoxic tumor tissues is an attractive strategy to overcome this hypoxia-associated radioresistance. Herein, we report the generation of submicron-sized particles comprising myoglobin fused to the crystal-forming domain of Cry3Aa protein for the targeted delivery of oxygen to cancer cells. We demonstrate that myoglobin-containing particles were successfully produced in Bacillus thuringiensis with the assistance of the Cry3Aa domain I. Furthermore, these particles could be genetically modified to incorporate the cell penetrating peptide TAT and cell targeting peptide A549.1, resulting in particles that exhibited improved cellular uptake and targeting toward A549 cells. Notably, these myoglobin-containing particles increased the intracellular oxygen levels of A549 cells and thereby sensitized them to radiation. These findings suggest that the targeted delivery of O2-bound myoglobin could be an effective approach to enhance the efficacy of radiotherapy.

12.
J Am Chem Soc ; 142(22): 9879-9883, 2020 06 03.
Article in English | MEDLINE | ID: mdl-32407637

ABSTRACT

Cry3Aa is a protein that forms crystals naturally in the bacterium Bacillus thuringiensis. Here we report that coexpression of Cry3Aa and a Proteus mirabilis lipase without recombinant fusion results in the efficient passive entrapment of the lipase within the nanoporous channels of the resulting crystals. This Cry3Aa crystal-mediated entrapment provides multiple benefits to the lipase including a high enzyme loading, significantly improved thermostability, increased proteolytic resistance, and the ability to be utilized as a recyclable biodiesel catalyst. These characteristics, along with its greatly simplified method of isolation, highlight the potential of Cry3Aa crystal-mediated enzyme entrapment for use in biocatalysis and other biotechnological applications.


Subject(s)
Bacillus thuringiensis Toxins/chemistry , Endotoxins/chemistry , Hemolysin Proteins/chemistry , Bacillus thuringiensis Toxins/metabolism , Crystallography, X-Ray , Endotoxins/metabolism , Hemolysin Proteins/metabolism , Models, Molecular
13.
Biotechnol Biofuels ; 12: 165, 2019.
Article in English | MEDLINE | ID: mdl-31297153

ABSTRACT

BACKGROUND: We have recently developed a one-step, genetically encoded immobilization approach based on fusion of a target enzyme to the self-crystallizing protein Cry3Aa, followed by direct production and isolation of the fusion crystals from Bacillus thuringiensis. Using this approach, Bacillus subtilis lipase A was genetically fused to Cry3Aa to produce a Cry3Aa-lipA catalyst capable of the facile conversion of coconut oil into biodiesel over 10 reaction cycles. Here, we investigate the fusion of another lipase to Cry3Aa with the goal of producing a catalyst suitable for the conversion of waste cooking oil into biodiesel. RESULTS: Genetic fusion of the Proteus mirabilis lipase (PML) to Cry3Aa allowed for the production of immobilized lipase crystals (Cry3Aa-PML) directly in bacterial cells. The fusion resulted in the loss of PML activity, however, and so taking advantage of its genetically encoded immobilization, directed evolution was performed on Cry3Aa-PML directly in its immobilized state in vivo. This novel strategy allowed for the selection of an immobilized PML mutant with 4.3-fold higher catalytic efficiency and improved stability. The resulting improved Cry3Aa-PML catalyst could be used to catalyze the conversion of waste cooking oil into biodiesel for at least 15 cycles with minimal loss in conversion efficiency. CONCLUSIONS: The genetically encoded nature of our Cry3Aa-fusion immobilization platform makes it possible to perform both directed evolution and screening of immobilized enzymes directly in vivo. This work is the first example of the use of directed evolution to optimize an enzyme in its immobilized state allowing for identification of a mutant that would unlikely have been identified from screening of its soluble form. We demonstrate that the resulting Cry3Aa-PML catalyst is suitable for the recyclable conversion of waste cooking oil into biodiesel.

14.
Biomaterials ; 217: 119286, 2019 10.
Article in English | MEDLINE | ID: mdl-31284125

ABSTRACT

Antimicrobial peptides (AMPs) have recently attracted great attention due to their rapid action, broad spectrum of activity, and low propensity of resistance development. The successful application of AMPs in the treatment of intracellular infections, however, remains a challenge because of their low penetration efficiency into the pathogen's intracellular niche. Herein, we report that sub-micrometer-sized crystals of the protein Cry3Aa formed within Bacillus thuringiensis are readily and specifically taken up by macrophages. We demonstrate that these protein crystals efficiently encapsulate a known antileishmanial peptide, dermaseptin S1 (DS1), and thereby promote improved cellular uptake of DS1 and its lysosomal accumulation in macrophages. Notably, this targeted delivery of DS1 results in enhanced in vitro and in vivo antileishmanial activity, as well as reduced toxicity to the host macrophages. These findings suggest that the Cry3Aa crystal can be an effective delivery platform for AMPs to treat intramacrophage infections.


Subject(s)
Antimicrobial Cationic Peptides/pharmacology , Bacterial Proteins/chemistry , Drug Delivery Systems , Endotoxins/chemistry , Hemolysin Proteins/chemistry , Macrophages, Peritoneal/drug effects , Macrophages, Peritoneal/parasitology , Amphibian Proteins/pharmacology , Animals , Bacillus thuringiensis Toxins , Bacterial Proteins/toxicity , Bacterial Proteins/ultrastructure , Cell Line, Tumor , Endotoxins/toxicity , Female , Hemolysin Proteins/toxicity , Hemolysin Proteins/ultrastructure , Hemolysis/drug effects , Humans , Inhibitory Concentration 50 , Leishmania/drug effects , Lysosomes/drug effects , Lysosomes/metabolism , Mice, Inbred BALB C
15.
JAMA Intern Med ; 178(9): 1182-1189, 2018 09 01.
Article in English | MEDLINE | ID: mdl-30083727

ABSTRACT

Importance: Approximately half of patients with chronic conditions are nonadherent to prescribed medications, and interventions have been only modestly effective. Objective: To evaluate the effect of a remotely delivered multicomponent behaviorally tailored intervention on adherence to medications for hyperlipidemia, hypertension, and diabetes. Design, Setting, and Participants: Two-arm pragmatic cluster randomized controlled trial at a multispecialty group practice including participants 18 to 85 years old with suboptimal hyperlipidemia, hypertension, or diabetes disease control, and who were nonadherent to prescribed medications for these conditions. Interventions: Usual care or a multicomponent intervention using telephone-delivered behavioral interviewing by trained clinical pharmacists, text messaging, pillboxes, and mailed progress reports. The intervention was tailored to individual barriers and level of activation. Main Outcomes and Measures: The primary outcome was medication adherence from pharmacy claims data. Secondary outcomes were disease control based on achieved levels of low-density lipoprotein cholesterol, systolic blood pressure, and hemoglobin A1c from electronic health records, and health care resource use from claims data. Outcomes were evaluated using intention-to-treat principles and multiple imputation for missing values. Results: Fourteen practice sites with 4078 participants had a mean (SD) age of 59.8 (11.6) years; 45.1% were female. Seven sites were each randomized to intervention or usual care. The intervention resulted in a 4.7% (95% CI, 3.0%-6.4%) improvement in adherence vs usual care but no difference in the odds of achieving good disease control for at least 1 (odds ratio [OR], 1.10; 95% CI, 0.94-1.28) or all eligible conditions (OR, 1.05; 95% CI, 0.91-1.22), hospitalization (OR, 1.02; 95% CI, 0.78-1.34), or having a physician office visit (OR, 1.11; 95% CI, 0.91-1.36). However, intervention participants were significantly less likely to have an emergency department visit (OR, 0.62; 95% CI, 0.45-0.85). In as-treated analyses, the intervention was associated with a 10.4% (95% CI, 8.2%-12.5%) increase in adherence, a significant increase in patients achieving disease control for at least 1 eligible condition (OR, 1.24; 95% CI, 1.03-1.50), and nonsignificantly improved disease control for all eligible conditions (OR, 1.18; 95% CI, 0.99-1.41). Conclusions and Relevance: A remotely delivered multicomponent behaviorally tailored intervention resulted in a statistically significant increase in medication adherence but did not change clinical outcomes. Future work should focus on identifying which groups derive the most clinical benefit from adherence improvement efforts. Trial Registration: ClinicalTrials.gov identifier: NCT02512276.


Subject(s)
Diabetes Mellitus/drug therapy , Hyperlipidemias/drug therapy , Hypertension/drug therapy , Medication Adherence , Pharmaceutical Services/organization & administration , Text Messaging , Adolescent , Adult , Aged , Aged, 80 and over , Antihypertensive Agents/therapeutic use , Chronic Disease , Female , Follow-Up Studies , Humans , Hypoglycemic Agents/therapeutic use , Hypolipidemic Agents/therapeutic use , Intention to Treat Analysis , Male , Middle Aged , Prospective Studies , Young Adult
16.
Sci Rep ; 8(1): 12783, 2018 08 24.
Article in English | MEDLINE | ID: mdl-30143735

ABSTRACT

The use of immobilized enzymes as biocatalysts has great potential to improve the efficiency and environmental sustainability of many industrial processes. Here, we report a novel approach that allows for the direct production of a highly active immobilized lipase within the bacterium Bacillus thuringiensis. Cry3Aa-lipA crystals were generated by genetically fusing Bacillus subtilis lipase A to Cry3Aa, a protein that naturally forms crystals in the bacteria. The crystal framework significantly stabilized the lipase against denaturation in organic solvents and high temperatures, resulting in a highly efficient fusion crystal that could catalyze the conversion of triacylglycerols to fatty acid methyl ester biodiesel to near-completion over 10 cycles. The simplicity and robustness of the Cry-fusion crystal (CFC) immobilization system could make it an appealing platform for generating industrial biocatalysts for multiple bioprocesses.


Subject(s)
Biofuels , Biotechnology/methods , Enzymes, Immobilized/metabolism , Lipase/genetics , Bacillus thuringiensis/ultrastructure , Bacillus thuringiensis Toxins , Bacterial Proteins/metabolism , Bacterial Proteins/ultrastructure , Catalysis , Crystallization , Endotoxins/metabolism , Escherichia coli/metabolism , Escherichia coli/ultrastructure , Hemolysin Proteins/metabolism , Hemolysin Proteins/ultrastructure , Kinetics , Lipase/metabolism , Recombinant Fusion Proteins/metabolism
17.
Sci Rep ; 8(1): 4171, 2018 03 08.
Article in English | MEDLINE | ID: mdl-29520098

ABSTRACT

Many cancers adeptly modulate metabolism to thrive in fluctuating oxygen conditions; however, current tools fail to image metabolic and vascular endpoints at spatial resolutions needed to visualize these adaptations in vivo. We demonstrate a high-resolution intravital microscopy technique to quantify glucose uptake, mitochondrial membrane potential (MMP), and SO2 to characterize the in vivo phentoypes of three distinct murine breast cancer lines. Tetramethyl rhodamine, ethyl ester (TMRE) was thoroughly validated to report on MMP in normal and tumor-bearing mice. Imaging MMP or glucose uptake together with vascular endpoints revealed that metastatic 4T1 tumors maintained increased glucose uptake across all SO2 ("Warburg effect"), and also showed increased MMP relative to normal tissue. Non-metastatic 67NR and 4T07 tumor lines both displayed increased MMP, but comparable glucose uptake, relative to normal tissue. The 4T1 peritumoral areas also showed a significant glycolytic shift relative to the tumor regions. During a hypoxic stress test, 4T1 tumors showed significant increases in MMP with corresponding significant drops in SO2, indicative of intensified mitochondrial metabolism. Conversely, 4T07 and 67NR tumors shifted toward glycolysis during hypoxia. Our findings underscore the importance of imaging metabolic endpoints within the context of a living microenvironment to gain insight into a tumor's adaptive behavior.


Subject(s)
Intravital Microscopy/methods , Mammary Neoplasms, Animal , Neovascularization, Pathologic , Optical Imaging/methods , Organometallic Compounds/pharmacology , Tomography, X-Ray Computed/methods , Animals , Cell Line, Tumor , Female , Mammary Neoplasms, Animal/blood supply , Mammary Neoplasms, Animal/diagnostic imaging , Mammary Neoplasms, Animal/metabolism , Mice , Mice, Nude , Neovascularization, Pathologic/diagnostic imaging , Neovascularization, Pathologic/metabolism , Tumor Microenvironment
18.
Sci Rep ; 7(1): 17487, 2017 12 13.
Article in English | MEDLINE | ID: mdl-29235516

ABSTRACT

Hsp90 has been studied extensively as a therapeutic target in breast cancer in pre-clinical and clinical trials, demonstrating a variety of roles in metastatic progression. The evidence to date suggests a compelling opportunity to leverage attributes of Hsp90 expression beyond therapeutics with potential applications in breast cancer diagnosis, prognosis, and recurrence risk assessment. In this study, we developed a completely non-destructive strategy using HS-27, a fluorescently-tethered Hsp90 inhibitor, to assay Hsp90 expression on intact tissue specimens with comparable contrast to in vivo administration routes, and demonstrate the feasibility of our approach in breast cancer patients. In addition to Hsp90 inhibition being most effective in glycolytic tumors, we found ectopic Hsp90 expression to be highest in glycolytic tumors reinforcing its role as an indicator of aggressive disease. This work sets the stage for immediately using Hsp90 to improve outcomes for breast cancer patients without affecting traditional care pathways.


Subject(s)
Breast Neoplasms/metabolism , Breast/metabolism , Fluorescent Dyes , HSP90 Heat-Shock Proteins/metabolism , Animals , Biomarkers, Tumor/metabolism , Biopsy, Large-Core Needle , Breast/diagnostic imaging , Breast/pathology , Breast Neoplasms/diagnostic imaging , Breast Neoplasms/pathology , Cell Line, Tumor , Cell Membrane/metabolism , Cell Membrane/pathology , Female , Glycolysis , HSP90 Heat-Shock Proteins/antagonists & inhibitors , Humans , Mice, Nude , Neoplasm Transplantation , Optical Imaging , Oxidation-Reduction , Receptor, ErbB-2/metabolism , Ultrasonography, Interventional , Ultrasonography, Mammary
19.
BMC Public Health ; 17(1): 127, 2017 01 28.
Article in English | MEDLINE | ID: mdl-28129762

ABSTRACT

BACKGROUND: The incidence of breast cancer in Asia is increasing because of urbanization and lifestyle changes. In the developing countries in Asia, women present at late stages, and mortality is high. Mammographic screening is the only evidence-based screening modality that reduces breast cancer mortality. To date, only opportunistic screening is offered in the majority of Asian countries because of the lack of justification and funding. Nevertheless, there have been few reports on the effectiveness of such programmes. In this study, we describe the cancer detection rate and challenges experienced in an opportunistic mammographic screening programme in Malaysia. METHODS: From October 2011 to June 2015, 1,778 asymptomatic women, aged 40-74 years, underwent subsidised mammographic screening. All patients had a clinical breast examination before mammographic screening, and women with mammographic abnormalities were referred to a surgeon. The cancer detection rate and variables associated with a recommendation for adjunct ultrasonography were determined. RESULTS: The mean age for screening was 50.8 years and seven cancers (0.39%) were detected. The detection rate was 0.64% in women aged 50 years and above, and 0.12% in women below 50 years old. Adjunct ultrasonography was recommended in 30.7% of women, and was significantly associated with age, menopausal status, mammographic density and radiologist's experience. The main reasons cited for recommendation of an adjunct ultrasound was dense breasts and mammographic abnormalities. DISCUSSION: The cancer detection rate is similar to population-based screening mammography programmes in high-income Asian countries. Unlike population-based screening programmes in Caucasian populations where the adjunct ultrasonography rate is 2-4%, we report that 3 out of 10 women attending screening mammography were recommended for adjunct ultrasonography. This could be because Asian women attending screening are likely premenopausal and hence have denser breasts. Radiologists who reported more than 360 mammograms were more confident in reporting a mammogram as normal without adjunct ultrasonography compared to those who reported less than 180 mammograms. CONCLUSION: Our subsidised opportunistic mammographic screening programme is able to provide equivalent cancer detection rates but the high recall for adjunct ultrasonography would make screening less cost-effective.


Subject(s)
Breast Neoplasms/diagnosis , Early Detection of Cancer/statistics & numerical data , Mammography/statistics & numerical data , Mass Screening/statistics & numerical data , Adult , Aged , Breast Neoplasms/economics , Breast Neoplasms/prevention & control , Cost-Benefit Analysis , Early Detection of Cancer/economics , Female , Humans , Incidence , Income , Malaysia , Mammography/economics , Mass Screening/economics , Middle Aged
20.
Am Heart J ; 180: 90-7, 2016 Oct.
Article in English | MEDLINE | ID: mdl-27659887

ABSTRACT

BACKGROUND: Approximately half of patients with chronic cardiometabolic conditions are nonadherent with their prescribed medications. Interventions to improve adherence have been only modestly effective because they often address single barriers to adherence, intervene at single points in time, or are imprecisely targeted to patients who may not need adherence assistance. OBJECTIVE: To evaluate the effect of a multicomponent, behaviorally tailored pharmacist-based intervention to improve adherence to medications for diabetes, hypertension, and hyperlipidemia. TRIAL DESIGN: The STIC2IT trial is a cluster-randomized pragmatic trial testing the impact of a pharmacist-led multicomponent intervention that uses behavioral interviewing, text messaging, mailed progress reports, and video visits. Targeted patients are those who are nonadherent to glucose-lowering, antihypertensive, or statin medications and who also have evidence of poor disease control. The intervention is tailored to patients' individual health barriers and their level of health activation. We cluster-randomized 14 practice sites of a large multispecialty group practice to receive either the pharmacist-based intervention or usual care. STIC2IT has enrolled 4,076 patients who will be followed up for 12months after randomization. The trial's primary outcome is medication adherence, assessed using pharmacy claims data. Secondary outcomes are disease control and health care resource utilization. CONCLUSION: This trial will determine whether a technologically enabled, behaviorally targeted pharmacist-based intervention results in improved adherence and disease control. If effective, this strategy could be a scalable method of offering tailored adherence support to those with the greatest clinical need.


Subject(s)
Chronic Disease/drug therapy , Medication Adherence , Pharmaceutical Services , Telemedicine , Diabetes Mellitus/drug therapy , Humans , Hyperlipidemias/drug therapy , Hypertension/drug therapy , Intention to Treat Analysis , Prospective Studies , Research Design
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