Biotechnology and applied biochemistry最新文献

Exosomes are a type of membrane vesicle secreted into the extracellular medium by most cell types. They have a great potential for clinical practice as noninvasive biomarkers for diagnosis of various diseases, prognosis, and monitoring of therapy, which stimulates the development of simple methods for isolating exosomes from biological fluids. A novel affine material based on aminosilanized superparamagnetic core‒shell nanoparticles for fast isolation of urinary exosomes is reported. Iron oxide nanoparticles coated with amino organosilane have been synthesized. The structural and magnetic characteristics of the resulting nanoparticles have been studied by transmission electron microscopy and ferromagnetic resonance. The surface of the synthesized nanoparticles has been chemically functionalized with lectin (concanavalin A), and the efficiency of the obtained material as a sorbent for affine exosome isolation from human urine has been demonstrated. A highly purified fraction of exosomes 90-200 nm in size has been obtained. The exosomal nature of the isolated vesicles has been confirmed by bioluminescent solid-phase microassay of tetrasporine receptor markers. The presence of exosomal miR-21 in the isolated human urine exosome samples has been established.

Osteoarthritis (OA) is a degenerative joint disorder characterized by progressive cartilage degradation. Excessive oxidative stress (OS), inflammatory responses, extracellular matrix breakdown, and cellular senescence of chondrocytes play crucial roles in the pathological development of OA. Currently, curing OA remains a significant challenge. In this study, we aimed to elucidate the protective effects of Annexin A1 protein Mimetic Peptide (Ac2-26) against tumor necrosis factor-α (TNF-α)-induced damage in CHON-001 chondrocytes by assessing cellular senescence, OS, and the expression levels of matrix metalloproteinase-13 (MMP-13) and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)-4. Our results show that Ac2-26 mitigated the reduction of telomerase activity and the exacerbation of cellular senescence induced by TNF-α in CHON-001 chondrocytes. Treatment with TNF-α led to decreased expression of the human telomerase reverse transcriptase gene and increased expression of the telomeric repeat-binding factor 2 gene, which were reversed by Ac2-26 treatment. The TNF-α-induced increases in the gene and protein expressions of p53 and p16 were restored by Ac2-26 in a dose-dependent manner. Additionally, we found that TNF-α caused elevations in the mRNA and protein levels of MMP-13 and ADAMTS-4, which were reduced by Ac2-26 in a dose-dependent fashion. Furthermore, TNF-α triggered the activation of nuclear factor κ-B (NF-κB) by increasing the levels of phosphorylated NF-κB p65 and the luciferase activity of NF-κB. Notably, Ac2-26 alleviated OS by reducing mitochondrial reactive oxygen species levels and promoting the activation of NF-E2-related factor 2 (Nrf2) in TNF-α-challenged CHON-001 chondrocytes. Silencing Nrf2 abolished the Ac2-26-induced activation of NF-κB and cellular senescence in CHON-001 chondrocytes. Collectively, these findings offer new insights into the potential therapeutic use of Ac2-26 for treating OA.

Cisplatin, the pioneering heavy metal compound, stands out as a potent drug for the treatment of various solid tumors. However, its clinical utility is hampered by notable toxicity and adverse effects, particularly nephrotoxicity. The potency of rutecarpine, a phytochemical, in mitigating cisplatin-induced nephrotoxicity was assessed in the present study. In this experimental setup, healthy male Wistar rats were grouped into four and Group I rats served as the control group, receiving only vehicle control. Group II rats were subjected to cisplatin treatment alone, administered intraperitoneally at a dosage of 7 mg/kg body weight on the 19th, 20th, and 21st days. Group III and IV rats were orally administered with rutecarpine at doses of 10 and 20 mg/kg body weight, respectively, starting from Day 1 and continuing daily for 21 days. Additionally, they were injected intraperitoneally with cisplatin at the same dosage and schedule as Group II. Relative kidney weight and renal biochemical markers blood urea nitrogen, lactate dehydrogenase, serum urea, and creatinine were measured to assess rutecarpine inhibitory potency against cisplatin toxicity. Markers of oxidative damage and antioxidants levels were quantified in the ruteacarpine- and cisplatin-treated rats. The study investigated the anti-inflammatory property of rutecarpine in cisplatin-induced nephrotoxicity by analyzing inflammatory cytokines. Renal tissue levels of monocyte chemoattractant protein-1, intercellular adhesion molecule-1, high-mobility group box 1, and nuclear factor kappa B, key markers of nephrotoxicity, were quantified to assess rutecarpine's potential to mitigate cisplatin-triggered damage. Histopathological examinations were performed to confirm the impact of rutecarpine against cisplatin-induced nephrotoxicity. Treatment with rutecarpine notably reduced renal biochemical markers, prevented renal edema, and attenuated oxidative stress-induced damage in cisplatin-treated rats. Both inflammatory and nephrotoxicity markers showed significant decreases in rats treated with rutecarpine along with cisplatin. Histological analysis affirmed that rutecarpine pretreatment effectively prevented cisplatin-induced nephrotoxicity. The study findings demonstrate that rutecarpine ameliorates cisplatin-triggered nephrotoxicity through its antioxidant and anti-inflammatory properties, suggesting that rutecarpine supplementation alongside cisplatin treatment could potentially reduce nephrotoxicity in cancer patients.

Endometrial cancer is the sixth most common gynecologic cancer, and has been reported as a malignancy arising due to the idiopathic effects of certain anticancer agents. Tamoxifen is the drug of choice in ER-positive breast cancer, and several studies have shown better disease-free survival in these patients. However, the long-term usage of tamoxifen has been associated with resistance and risk for endometrial malignancy. A direct mechanistic basis for tamoxifen-induced endometrial tumorigenesis is still unclear. Hyperactivation of PAK1 in endometrial cancer correlates with poor overall survival. The present study demonstrates that tamoxifen treatment induces nuclear localization of PAK1 in endometrial carcinoma cells. This nuclear transit is mediated through JAK2 phosphorylation of PAK1 and binding of β-PIX. In addition, a computational approach involving molecular modeling and simulation of phosphorylated and unphosphorylated forms of PAK1 was used to elucidate the dynamics of nuclear localization. Thus, PAK1 phosphorylation by JAK2 is a prerequisite for its nuclear localization and its tumorigenic effects on endometrial cancer cells.

Obesity stands out as one of the most significant health problems in the modern world. The prevalence of high-calorie diets (HCDs) globally exacerbates this condition. Throughout history, plants and plant-derived food products have been utilized for medicinal purposes, demonstrating their efficacy in the treatment and prevention of various diseases. Gundelia tournefortii (GT), a plant of interest, is known to possess beneficial properties. Hence, this study aimed to investigate the immunotoxic and neurotoxic effects of two different doses of GT plant extract on the liver, brain, and heart tissues of obese rats. For this purpose, Wistar male rats were divided into four groups: "CG," "HCDG," "HCDGUN1," and "HCDGUN2" At the conclusion of the study, adenosine deaminase (ADA) and myeloperoxidase (MPO) activities, as well as acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) biomarkers, were evaluated in the liver, heart, and brain tissues. The study results revealed a statistically significant increase in ADA and MPO activities in the HCDG group compared to the CG group, alongside a significant decrease in the HCDGUN groups compared to the HCDG group. Regarding AChE and BChE activities, a statistically significant decrease was observed in the HCDG group compared to the CG group, whereas an increase was noted in the HCDGUN groups relative to the HCDG group, with the latter approaching values similar to those of the control group. In conclusion, the intake of GT plant extract exhibited positive effects on the immunotoxic and neurotoxic effects induced by HCD in rats with an experimental obesity model, as evidenced by tissue biomarker evaluations.

Regulating secondary metabolite (SM) in Myxococcus xanthus bears the potential to influence the formation of important natural products with various biological activities. The authors of this study have previously found that the detectable levels of two proteins (4-hydroxyphenylpyruvate dioxygenase [HppD] and a Hsp90-like protein  [HtpG]) are affected by ROK inactivation. As evidence, the current study was designed to elucidate the possible role of these two proteins in regulating the SMs' biosynthesis in this bacterium. To begin with, inactivation of the corresponding genes was carried out, and two mutant strains (M. xanthus hppD^- and htpG^-) were constructed. Subsequently, high-performance liquid chromatography coupled with mass spectrometry analysis for the metabolic extracts of the mutants revealed a significant reduction in the production of several SMs, like DKxanthene, myxalamide A, and myxochromide A, in comparison to the wild type. Furthermore, electrophoretic mobility shift assays using purified ROK protein suggested a direct binding on the genes' promoter region encoding the two proteins under study. It is therefore possible to conclude that hppD and htpG genes are implicated in the bacterium SMs' biosynthetic regulatory cascade, which seems to be directly regulated by the ROK protein. The present study provides additional evidence to a previous investigation showing the pleiotropic regulatory role of ROK on the production of SMs in M. xanthus.

Metallo-β-lactamases (MBLs), enzymes of class B, employ zinc ions to degrade β-lactam antibiotics such as penicillins, cephalosporins, carbapenems, and cephamycins. Carbapenem-resistant Acinetobacter baumannii (CRAB) is linked to the existence of carbapenemase enzymes such as oxacillinase and MBL. The most prevalent resistance mechanisms include imipenemases (IMP), verona integron-encoded MBL, and New Delhi MBL-1. The effectiveness of current antibiotics against the MBL enzyme is limited due to the presence of metal ions, underscoring the need for new antimicrobial agents. Recent research has demonstrated that natural compounds can effectively inhibit MBL. This study aims to screen natural phytochemicals against IMP-2 MBL using in silico virtual screening techniques via AutoDock Vina and molecular dynamic simulations with GROMACS for 200 ns, followed by molecular mechanics/Poisson‒Boltzmann surface area analysis. This procedure identified new lead molecules against A. baumannii that produce IMP. A total of 588 natural compounds were screened against IMP, along with the imipenem substrate and known inhibitors of L-captopril. The top four compounds, N025-0038 (NC1), N062-0008 (NC2), eupalitin, and Rosmorinic acid, demonstrated binding affinities of ‒8.5, ‒8.4, ‒7.5, and ‒7.2 kcal/mol, respectively. The structural stability of these complexes was observed to be maintained throughout the simulation in a dynamic environment, as determined by molecular dynamics trajectory analysis, and all these compounds met the SWISS-ADME (adsorption, distribution, metabolism, and excretion) properties. NC1 and NC2 compounds are considered potential drug molecules against IMP. However, while these selected compounds showed superior binding energy in computational analysis, further in vitro analysis is required to establish an effective drug regimen against A. baumannii that produces IMP.

The challenge with breast cancer is its ongoing high prevalence and difficulties in early detection and access to effective care. A solution lies in creating tailored metal-organic frameworks to encapsulate anticancer drugs, enabling precise and targeted treatment with less adverse effects and improved effectiveness. Zeolitic imidazolate framework-8 (ZIF-8) and carboplatin (CP)-loaded ZIF-8 were synthesized and characterized using various analytical techniques. High Resolution-transmission electron microscopy of ZIF-8 and CP@ZIF-8 indicates that the particles had a spherical shape and were nanosized. The drug release rate of CP is 98% under an acidic medium (pH 5.5) because of the dissolution of ZIF-8 into its coordinating ions, whereas 35% in a physiological medium (pH 7.4) with the addition of CP, the high porosity, and pore diameter of ZIF-8 decrease from 1243 to 1041 m²/g. Breast cancer MCF-7 cells were shown greater IC₅₀ in CP@ZIF-8 (15.01 ± 3.03 µg/mL) than free CP (34.98 ± 4.25 µg/mL) in an in vitro cytotoxicity assessment. The cytotoxicity of the CP@ZIF-8 against MCF-7 cells was studied using the methylthiazolyldiphenyl-tetrazolium bromide method. The morphological changes were examined using fluorescent staining (acridine orange-ethidium bromide and Hoechst 33258) methods. The comet assay assessed the DNA fragmentation (single-cell gel electrophoresis). The results from the study revealed that CP@ZIF-8 can be used in the treatment of breast cancer.

In recent years, genistein has garnered increased interest for its ability to inhibit numerous deregulated targets associated with cancer progression and induction of programmed cell death and antiproliferative activities in human carcinoma cells. Cancer etiology is influenced via multiple disrupted signaling pathways. This study therefore directed toward investigating genistein efficacy in modulating mRNA expression levels of two crucial Human Pappiloma Virus (HPV) (E7 and E6) oncogenes for cancer treatment. Moreover, the inhibitory effects of genistein for HPV (E7 and E6) oncogenes in cervical carcinoma have not yet been reported. Current study investigated inhibitory potential of genistein in HPV (E7 and E6) oncogenes in HeLa cells. These oncogenes are known to deactivate many tumor suppressor proteins (p53 and pRB). Genistein therapy resulted in decreased cell proliferation and increased cell accumulation in the G (G0/G1) phase in HeLa cell lines. In addition, genistein therapy has resulted in the suppression of HPV (E7 and E6) gene expression and simultaneously increasing expression levels of p53 and pRB mRNA levels. As a consequence, there has been an activation of a series of caspases (3, 8, and 9), resulting in their cleavage. Consequently, our data suggests that genistein could be a powerful candidate for treating cervical cancer by targeting two important oncogenes involved in viral development. However, more in vitro research on primary cervical cancer cells is required to validate the clinically relevant efficacy of genistein against cervical cancer.

One of the main goals of contemporary biotechnology has been the development of novel immobilized enzyme formulations. In the present study, the industrially important β-galactosidase was trapped in a polyvinyl alcohol (PVA) gel to immobilize it. The optimization of immobilization method and characterization of the immobilized enzyme were studied. The results were compared with free enzymes. The results indicate that the optimal temperature range for the enzyme to be at following immobilization is between 40°C and 50°C. At pH 7, the optimal pH, the activity increased, the V_max value increased from 1.936 to 2.495 U mg^‒1, and the K_m value decreased from 4.861 to 0.982 mM. Depending on how stable the immobilized enzyme when stored, β-galactosidases immobilized on PVA gels showed 52.87% activity at the end of the seventh week and 58.86% activity at the end of the fifth week. Their initial activity subsided after three reuses. The final result was 66%. Therefore, one may argue that it increases the catalytic effect of the enzyme. As a result, it has been found that immobilized β-galactosidase has more potent enzymatic properties than free β-galactosidase, which may make it more advantageous for industrial processes. Further studies could delve deeper into the mechanistic aspects of the immobilization process in an effort to improve optimization and tailor the immobilized enzyme to specific industrial needs.