Biotechnology and applied biochemistry最新文献

Alpha-synuclein oligomers play a crucial role in the early diagnosis of Parkinson's disease (PD). In this study, a mercaptoundecanoic acid (MUA)-capped gold nanorod (GNR)-coated and chitosan (CH)-immobilized fiber optic probe has shown considerable sensitivity of its detection. The proposed U-shaped fiber optic biosensor based on localized surface plasmon resonance (LSPR) was applied to detect α-syn oligomer (OA) biomarker. By analyzing OA concentrations, the biosensor achieved a limit of detection of (LOD) 11 pM within the concentration range of 10-100 pM and the sensitivity value was found as 502.69 Δλ/RIU. Upon analysis of the CV% (coefficient of variation) and accuracy/recovery values, it is revealed that the sensor successfully fulfilled the criteria for success, displaying accuracy/recovery values within the range of 80%-120% and CV% values below 20%. This sensor presents significant advantages, including high sensitivity, specificity, and ability to detect very low concentrations of OA. In conclusion, the suggested U-shaped fiber optic biosensor has the potential to be valuable in the early detection of PD from a clinical perspective.

Heparinases, including heparinases I-III (HepI, HepII, and HepIII, respectively), are important tools for producing low-molecular-weight heparin, an improved anticoagulant. The poor thermostability of heparinases significantly hinders their industrial and laboratory applications. To improve the thermostability of heparinases, we applied a rigid linker (EAAAK)₅ (R) and a flexible linker (GGGGS)₅ (F) to fuse maltose-binding protein (MBP) and HepI, HepII, and HepIII from Pedobacter heparinus, replacing the original linker from the plasmid pMAL-c2X. Compared with their parental fusion protein, MBP-fused HepIs, HepIIs, and HepIIIs with linkers (EAAAK)₅ or (GGGGS)₅ all displayed enhanced thermostability (half-lives at 30°C: 242%-464%). MBP-fused HepIs and HepIIs exhibited higher specific activity (127%-324%), whereas MBP-fused HepIIIs displayed activity similar to that of their parental fusion protein. Kinetics analysis revealed that MBP-fused HepIIs showed a significantly decreased affinity toward heparin with increased K_m values (397%-480%) after the linker replacement, whereas the substrate affinity did not change significantly for MBP-fused HepIs and HepIIIs. Furthermore, it preliminarily appeared that the depolymerization mechanism of these fusion proteins may not change after linker replacement. These findings suggest the superior enzymatic properties of MBP-fused heparinases with suitable linker designs and their potential for the bioproduction of low-molecular-weight heparin.

Alzheimer's disease (AD) is a multifactorial disease in which environmental factors play a role. Among environmental factors, air pollution is a vital issue in modern life. Despite extensive considerations, it remains uncertain how pollution mediates neurodegeneration in AD. Beta-amyloids and hyperphosphorylated tau proteins are the two main pathological markers that have been studied in AD so far. Tau protein is basically a phosphoprotein whose functions are controlled by phosphorylation. The function of tau protein is to be located on the surface of microtubules and stabilize them. Studies have shown that phosphorylated tau protein (p-tau) exists in cis and trans conformations at Thr231, among which cis is highly neurotoxic. The Pin1 enzyme performs the conversion of cis to trans or vice versa. In this study, an experimental mouse model was designed to investigate the formation of cis p-tau by inducing air pollution. In this way, mice were randomly exposed to pollution at 2-week, 1-month, and 2-month intervals. We investigated the formation of phosphorylated cis tau form during air pollution on mouse brains using Western blots and immunofluorescence. The fluorescent imaging results and Western blotting analysis of mouse brains revealed a significant accumulation of cis p-tau in pollution-treated mice models compared to the healthy control mice. According to Western blot results, air pollution induction caused a significant decrease in Pin1 protein. The results clearly show that the tauopathy observed during air pollution is mediated through the formation of cis tau. Our findings unravel tauopathy mysteries upon pollution and would help find a possible therapeutic target to fight the devastating disorder caused by modern life.

Melanoma is known to be the most hazardous and life-threatening type of skin cancer. Although numerous treatments have been authorized in recent years, they often result in severe side effects and may not fully cure the disease. To combat this issue, immunotherapy has emerged as a promising approach for the prevention and treatment of melanoma. Specifically, the use of epitope melanoma vaccine, a subset of immunotherapy, has recently gained attention. The aim of this study was to create a multi-epitope melanoma vaccine using immunoinformatic methods. Two well-known antigens, NYESO-1 and MAGE-C2, were selected due to their strong immunogenicity and high expression in melanoma. To enhance the immunogenicity of the peptide vaccine, Brucella cell-surface protein 31 (BCSP31), the G5 domain of resuscitation-promoting factor B (RpfB) adjuvants, and the helper epitope of pan HLADR-binding epitope (PADRE) were incorporated to vaccine construct. These different segments were connected with suitable linkers and the resulting vaccine structure was evaluated for its physicochemical, structural, and immunological properties using computational tools. The designed vaccine was found to have satisfactory allergenicity, antigenicity, and physicochemical parameters. Additionally, a high-quality tertiary structure of the vaccine was achieved through modeling, refinement, and validation. Docking and molecular dynamics studies showed that the vaccine had a stable and appropriate interaction with the cognate TLR2 and TLR4 receptors during the simulation period. Finally, in silico immune simulation analysis revealed a significant increase in the levels of helper and cytotoxic T cells, as well as the cytokines interferon-gamma and interleukin-2, after repeated exposure to the melanoma vaccine. These results suggest that the designed vaccine has the potential to be an effective therapeutic option for melanoma. However, additional in vitro and in vivo validations are crucial to assess real-world efficacy and safety.

Glycated proteins are generated by binding of glucose to the proteins in blood stream through a nonenzymatic reaction. Hemoglobin A1c (HbA1c) is a glycated protein with glucose at the N-terminal of β-chain. HbA1c is extensively used as an indicator for assessing the blood glucose concentration in diabetes patients. There are different conventional clinical methods for the detection of HbA1c. However, enzymatic detection method has newly obtained great attention for its high precision and cost-effectiveness. Today, fructosyl peptide oxidase (FPOX) plays a key role in the enzymatic measurement of HbA1c, and different companies have marketed HbA1c assay systems based on FPOX. Recent investigations show that FPOX could be used in assaying HbA1 without requiring HbA1c primary digestion. It could also be applied as a biosensor for HbA1c detection. In this review, we have discussed the recent improvements of FPOX properties, different methods of FPOX purification, solubility, and immobilization, and also the use of FPOX in HbA1c biosensors.

Triple-negative breast cancer (TNBC) has short survival rates. This study aimed to prepare a novel formula of sorafenib, carbon nanotubes (CNTs), and folic acid to be tested as a drug delivery system targeting versus TNBC compared with free sorafenib and to evaluate the formula stability, in vitro pharmacodynamic, and in vivo pharmacokinetic properties. The formula preparation was done by the synthesis of polyethylene glycol bis amine linker, CNT PEGylation, folic acid attachment, and sorafenib loading. The prepared formula has been characterized using X-ray diffraction, Flourier-transform infrared, ¹HNMR, UV, high resolution-transmission electron microscope, field emission scanning electron microscopy, and Zeta potential. In vitro studies included drug release determination, MTT assay, flow cytometry to determine the apoptotic stage with percent, cell cycle analysis, and apoptotic marker assays for caspase-3, 8, 9, cytochrome c, and BCL-2. The in vivo study was performed to determine bioavailability and half-life in rats. The in vitro MTT antiproliferative assay revealed that the formula was threefold more cytotoxic toward TNBC cells than free sorafenib, and the flow cytometry showed a significant increase in apoptosis and necrosis. The formula has a greater inhibitory effect on BCL-2 and a lessening effect on cytochrome c and caspases 3, 8, and 9 than free sorafenib. In vivo experiments proved that our novel formula was superior to free sorafenib by increasing bioavailability by eight times and prolonging the half-life by three times. These results confirmed the successful preparation of the desired formula with better pharmacodynamic and pharmacokinetic properties. These promising results may show a novel therapeutic strategy for TNBC patients.

Cardiotoxicity is the leading side effect of anthracycline-based chemotherapy. Therefore, it has gained importance to reveal chemotherapy-supporting strategies and reliable agents with their mechanisms of action. Tannic acid (TA), a naturally occurring plant polyphenol, has diverse physiological effects, including anti-inflammatory, anticarcinogenic, antioxidant, and radical scavenging properties. Therefore, this study was designed to investigate whether TA exerts a protective effect on mechanisms contributing to anthracycline-induced cardiotoxicity in rat heart tissues exposed to doxorubicin (DOX). Rats were randomly divided into control and experimental groups and treated with (18 mg/kg) DOX, TA (50 mg/kg), and DOX + TA during the 2 weeks. Cardiac gene markers and mitochondrial DNA (mtDNA) content were evaluated in the heart tissues of all animals. In addition to major metabolites, mRNA expression changes and biological activity responses of components of antioxidant metabolism were examined in the heart tissues of all animals. The expression of cardiac gene markers increased by DOX exposure was significantly reduced by TA treatment, whereas mtDNA content, which was decreased by DOX exposure, was significantly increased. TA also improved antioxidant metabolism members' gene expression and enzymatic activity, including glutathione peroxidase, glutathione s-transferase, superoxide dismutase, catalase, and thioredoxin reductase. This study provides a detailed overview of the current understanding of DOX-induced cardiotoxicity and preventive or curative measures involving TA.

Mycobacterium indicus pranii (MIP), a benign saprophyte with potent immunomodulatory attributes, holds a pivotal position in mycobacterial evolution, potentially serving as the precursor to the pathogenic Mycobacterium avium complex (MAC). Despite its established immunotherapeutic efficacy against leprosy and notable outcomes in gram-negative sepsis and COVID-19 cases, the genomic and biochemical features of MIP remain largely elusive. This study explores the uncharted territory of toxin-antitoxin (TA) systems within MIP, hypothesizing their role in mycobacterial pathogenicity regulation. Genome-wide screening, employing diverse databases, unveils putative TA modules in MIP, setting the stage for a comparative analysis with known modules in Mycobacterium tuberculosis, Mycobacterium smegmatis, Escherichia coli, and Vibrio cholerae. The study further delves into the TA network of MAC and Mycobacterium intracellulare, unraveling interactive properties and family characteristics of identified TA modules in MIP. This comprehensive exploration seeks to illuminate the contribution of TA modules in regulating virulence, habitat diversification, and the evolutionary pathogenicity of mycobacteria. The insights garnered from this investigation not only enhance our understanding of MIP's potential as a vaccine candidate but also hold promise in optimizing tuberculosis drug regimens for expedited recovery.

A new and innovative rolled graphene oxide (roll-GO)/poly-m-methylaniline (PmMA) core-shell nanocomposite has been successfully synthesized using an in situ polymerization technique. This eco-friendly and cost-effective material shows great promise due to its antimicrobial properties. The characterization of the nanocomposite involved X-ray diffraction and Fourier transform infrared spectroscopy to analyze its structure and functional groups, whereas scanning electron microscopy and transmission electron microscopy (TEM) were utilized to examine its morphology. TEM analysis revealed the formation of roll-GO, forming multi-walled tubes with inner and outer diameters of 50 and 70 nm, respectively. Optical analysis demonstrated an enhanced bandgap in the nanocomposite, with bandgap values of 2.38 eV for PmMA, 2.67 eV for roll-GO, and 1.65 eV for roll-GO/PmMA. The antibacterial efficacy of the nanocomposite was tested against Gram-positive bacteria, including Bacillus subtilis and Staphylococcus aureus, as well as Gram-negative bacteria such as Escherichia coli and Salmonella sp. The well diffusion method was used to determine the inhibition zones, revealing that the nanocomposite demonstrated broad-spectrum antibacterial activity against all the pathogens tested. The largest inhibition zones were observed for B. subtilis, followed by S. aureus, E. coli, and Salmonella sp. Notably, the inhibition zones increased when the samples were exposed to light compared to dark conditions, with increases of 33 and 18 mm noted for B. subtilis. This enhanced activity under light exposure is attributed to the photocatalytic properties of the nanocomposite. The antibacterial mechanism is based on both adsorption and degradation processes. Moreover, antibacterial activity was found to increase with increasing concentrations of nanoparticles, ranging from 100 to 500 ppm. This suggests that the nanocomposite has potential as an alternative to antibiotics, especially considering the growing issue of bacterial resistance. The promising results obtained from the inhibition zones make these nanocomposites suitable for various applications. Currently, the research team is working on the development of a prototype utilizing these antimicrobial particles within commercial bottles for sterilization purposes in factories and companies.

Ovarian cancer is one of the most prevalent malignancies among women. CircRNAs play key roles in the progression of ovarian cancer. This study aimed to investigate the mechanism of action of hsa_circ_0000129 and its effects on ovarian cancer. Expression of hsa_circ_0000129, tropomyosin 3 (TPM3), and miR-383-5p in ovarian cancer cell lines and tissue specimens was detected using qRT-PCR or western blotting. Cell counting kit-8 (CCK-8), colony formation, and transwell assays were performed to assess viability, proliferation, and migration of ovarian cancer cells. A xenograft model was used to study tumorigenicity of ovarian cancer cells in vivo. Luciferase and RNA immunoprecipitation assays were performed to determine binding between miR-383-5p and hsa_circ_0000129 or TPM3. Upregulation of hsa_circ_0000129 and TPM3 and downregulation of miR-383-5p were observed in ovarian cancer. Low hsa_circ_0000129 and TPM3 expression repressed viability, migration, and proliferation of ovarian cancer cells. Inhibition of miR-383-5p had a contrary effect. Furthermore, knockdown of hsa_circ_0000129 restricted the tumorigenicity of ovarian cancer cells. Mechanistically, hsa_circ_0000129 has a sponging effect on miR-383-5p, which targets TPM3. Hsa_circ_0000129 stimulated development of the malignant ovarian cancer phenotype by sponging miR-383-5p and releasing TPM3.