Journal of Applied Biotechnology Reports
Volume:10 Issue: 3, Summer 2023

Clostridium species can produce a wide variety of toxins. They block acetylcholine (ACh) release from presynaptic nerve terminals at the neuromuscular junctions. Botulinum neurotoxin is the deadliest toxin ever known to human knowledge. One of the most serious consequences of these toxins (BoNTA specifically) is flaccid muscle due to defective acetylcholine (ACh) release at the neuromuscular junction (NMJ) as a noticeable clinical symptom, resulting in irreversible botulinum toxicity. Interestingly, cosmetic and therapeutic applications have also been described for this agent. Thus, an urgent need is felt for rapid, precise, and cost-effective detection and real-time monitoring of these toxins. Using biosensors such as optical biosensors, electrochemical biosensors, feedback control systems (FSC) and aptamers is a method for detecting BoNTs. Optical biosensors use optical transducers for detection, which consist of fluorescence biosensors and surface plasmon resonance (SPR) biosensors. Electrochemical biosensors are based on the principle of straight transduction of the reaction rate into a current. They consist of impedimetric, voltammetric, amperometric, and impedance spectroscopy biosensors. Aptamers are oligonucleotide derivatives isolated by the SELEX approach. Aptamers are highly specific, very cost-effective, and quick. In this review study, the most common and effective detection methods, including novel methods, have been described and discussed briefly. In this review, our focus was on the main concepts and applications that have been achieved up to this date to diagnose the in-field botulism.

Some bacteria commonly found on plants can catalyze the freezing of water at a higher temperature than others, at or near 0 °C. The freezing point of pure water is about -40 °C and is initiated by creating ice nucleations. However, when ice nucleation proteins (INPs) are present, ice nucleations form at temperatures close to or above 0 °C. INPs are often attached to the outer membrane by a phosphatidylinositol anchor and are sometimes secreted extracellularly. The monomers of INPs in Pseudomonas syringae are 120 to 180 kDa. INP has three domains, and the central domain is highly repetitive. The central domain consists of the consensus sequence of eight amino acid repeats. Eight amino acid repeats create a 16-residue fragment, and three 16-residue fragments form the 48-residue fragment. Studies have shown that INPs may have a β-helical fold and interact with water through the repetitive motif. Most ice nucleation bacteria are gram-negative, including P. syringae, Pseudomonas viridiflava, Pseudomonas fluorescens, Xanthomonas compestris, Erwinia ananas, and Erwinia herbicola. For optimum protein activity, the presence of the complete bacterial cell is essential. INPs are influential in different aspects, including snowmaking, agriculture, freeze-concentration in the food industry, signal transduction, atmospheric applications as cloud condensation nuclei, and surface display (expression of a foreign protein on the cell surface for biotechnological purposes). This study provides a brief overview of ice nucleation proteins and their applications since ice nucleation is an important phenomenon that affects various aspects, from climate to biological systems.

The present study systematically reviews the studies on the application and effect of periodontal ligament stem cells (PDLSCs) in the regeneration of periodontal defect in animal and human models.

The databases of PubMed, Scopus, Cochrane Library, Embase, and ProQuest, as well as the Web of Science were searched for relevant published articles in English without time limit until August 2022. The eligibility criteria were the studies focusing on the use and effect of PDLSCs on periodontal regeneration. Exclusion criteria included the articles which did not report the extent of periodontal regeneration, and those failing to provide flow cytometry and differentiation tests to prove the stemness of PDLSCs.

In this review, 27 animal and 4 human studies meet the eligibility criteria. Human samples had periodontal disease, and various surgical periodontal defects had been created in the animals (mouse, rat, rabbit, dog, and sheep). Meta-analysis was not possible due to heterogeneity in study designs. Based on the literature review, there was inconsistency in the limited number of conducted human research. However, cementum, PDL, and bone regeneration increased in animal models in the PDLSCs group compared to the control ones. No complication in PDLSCs groups was reported.

The application of PDLSCs as one of tissue engineering components can impose beneficial effects on periodontal tissue regeneration in animal models. However, more human studies with higher quality are required to assess clinical efficacy of this method.

Melanocyte stem cells (MelSCs) might offer potential candidates for cell-based therapies against pigmentary disorders, such as vitiligo. However, the properties of MelSCs and their involvement in disease pathology are yet to be explored. In this study, MelSCs derived from the lesional (V-MelSCs) and unaffected regions of vitiligo patients (NV-MelSCs) were established, and compared their cellular, biological and molecular characteristics to that of MelSCs isolated from the skin of normal, unaffected individuals as control (C-MelSCs). MelSCs were isolated and expanded in vitro by explant culture. Growth kinetics, metabolic activity, cell viability, colony-forming ability, senescence activity, and cell cycle status of MelSCs were analyzed. Later, MelSCs were evaluated for the expression of marker genes, such as CD34, Pax3, Sox10, sFRP4, MITF, TYRP1, DCT, TYR, TGFα, and c-KIT. MelSCs derived from vitiligo patients had lower proliferation and metabolic activity despite showing unaltered morphological features. Significantly (P<0.05) decreased number of viable cells was observed in C-MelSCs and V-MelSCs in passage 3 (P3) compared to P1. The colonyforming assay revealed homogeneous distribution, but slightly larger and dense colonies in C-MelSCs compared to NV-MelSCs and V-MelSCs. All MelSCs showed a higher percentage in the G0/G1 phase of the cell cycle with low senescence activity. Finally, MelSCs from the skin of vitiligo exhibited lower expression levels of selected marker genes implicated in melanocyte development. MelSCs residing in hair follicle bulge of vitiligo patients possess marginally altered cellular, potency and biological characteristics. These findings underscore the challenges in establishing repigmentation therapy for vitiligo using autologous transplantation of MelSCs.

Abiotic limitations, like water deficit, high temperature, salinity, and cold are some of the main barrier agents to plant growth throughout the world. To obtain a comprehensive view of a plant’s response to abiotic stresses, we applied robust bioinformatics approaches including the integration of meta-analysis, weighted gene co-expression network analysis (WGCNA), and machine learning. In this paper, 32 samples from four different stresses were chosen for analysis. Cross-platform combination method was used to conduct meta-analysis. To find gene co-expression modules related to stress conditions WGCNA analysis was performed. Machine learning methods were applied to validate the most important hub genes. Meta-analysis detected 275 differential expression genes (DEGs) and WGCNA showed 28 distinct modules under those stresses. Seven potential hub genes (At1g07430 (HAI2), At5g52300 (LTI65), At1g60190 (PUB19), At5g50360, At1g77120 (ADH1), At1g56600 (GolS2), and At5g57050 were detected by network analysis and validated by machine learning methods. These genes are involved in different pathways of cellular response to abiotic stresses. Analysis indicates that among the hub genes, At5g50360 was identified as a novel candidate gene. As such, the At5g50360 can be used in plant breeding programs for the development of abiotic stress-tolerant crops.

Shiga-like toxin-producing E. coli (STEC) was first introduced as a human pathogen in 1982. STEC serotypes were isolated from animals, foods, and other samples. This serotype is the leading cause of single and epidemic Hemorrhagic colitis and Haemolytic uremic syndrome. STEC serotype produces two potent toxins named Shiga-like toxin 1 and 2, whose genomes are encoded by phage. These toxins have a cytopathic effect on intestinal epithelial cells that cause bloody diarrhea. This study aimed to design and evaluate a nanobiosensor based on the LSPR (Local Surface Plasmon Resonance) property of citrated gold nanoparticles (GNP), by modifying the pH of the GNP environment and conjugation (non-covalent bonding) of GNP with rabbit anti- Shiga-like toxin polyclonal antibody (IgG). In this process, the binding of gold nanoparticles to antibodies and the detection of Shiga-like toxin were confirmed using UV-visible and DLS methods and the sensitivity and specificity of the produced nanobioprobe were evaluated using the ELISA method. The results showed that the sensitivity of this method in detecting Shiga-like toxin is about 10 ng/ml and the visible color-changing of the nanoprobe suspension was confirmed for all vials containing the target antigen in less than 1 h. In conclusion, the advantage of the produced nanobioprobe over other methods is the detection of small quantities of analytes, low cost, and detection in less than 2 h.

Extracellular vesicles (EVs) are biomolecular messengers secreted by all types of cells. It passes messages through molecular cargoes such as proteins, nucleic acids, and lipids from the parent cell to the target cell. EVs derived from the plasma are used for minimally invasive biopsy and as a possible biomarker to monitor the progression and severity of the disease. In this study, the matrix-assisted laser desorption and ionization-time of flight mass spectrometry approach was used to characterize and study the protein fingerprint region of plasma-derived extracellular vesicles. At first, 3 ml of blood sample was collected from five boys of 5-10 years in sodium citrate tubes, and the samples were centrifuged within an hour to extract plasma. The total exosome isolation (TEI) method was used to obtain high-yield plasma-derived EVs, and the EVs were stored at -80 °C for further analysis. The isolated intact EVs were mixed with an optimal concentration of sinapinic acid matrix (20 mg/ml) in a 1:1 ratio for fingerprint analysis using matrix-assisted laser desorption/ionization–time of flight mass spectrometry (MALDI-TOF MS). We found that the following operational conditions yielded good and high-resolution spectra: broad mass range (2000- 20000 m/z), detector gain (30x), and laser shot (50, 300, and 1000) with 100% laser intensity. The obtained MALDI TOF spectral peaks of plasma EVs (pEVs) matched the reported biomarkers. Based on the analyses, we improved the crucial experimental conditions and identified five distinct peaks at m/z = 3315, 6630, 9421, 8875, and 8917. C4A, C3, and apolipoproteins A-II, C-I, C-II, and C-III were identified by comparing MALDI-TOF MS data with existing reports. MALDI-TOF MS-based EV analysis can support the development of protein biomarker screening tools for early diagnosis.

Acute myeloid leukemia (AML) is a heterogeneous and complex malignancy characterized by rapid cellular proliferation, an aggressive clinical course, and generally high mortality. Transforming growth factor-beta (TGF-β) plays a significant role in tumorigenesis. Bone morphogenetic protein 4 (BMP4) is a member of the TGF-β superfamily whose expression is mainly controlled by the Smad signaling pathway. Studies have shown that this protein can control and induce the expression of some microRNAs during the cancer treatment process. MiR-424-5p plays an essential role in various types of cancer at different stages of tumorigenesis, including the promotion and/or inhibition of tumorigenesis, regulation of tumor development in the tumor microenvironment, and influencing cancer chemotherapy outcomes. The aim of this study was to evaluate the induction of cell death in the U937 myeloid leukemia cell line co-cultured with genetically engineered adipose-derived stem cells (ADSCs) expressing a high level of BMP4 through miR-424-5p. The induction of cell death and apoptosis in the U937 cell line was assessed using MTT and Annexin V/ PI assays, respectively. The expression of miR-424 and TGF-β was determined in the co-culture system using real-time PCR. The results of MTT and Annexin V/ PI assays showed that BMP4-expressing adipose-derived stem cells (ADSCs) induced cell death in U937 cells in the co-culture system. Co-culture of engineered ADSCs with the U937 cell line led to the downregulation of miR-424 and TGF-β genes in U937 cells. In the current study, a new strategy based on BMP4 induction was designed to significantly suppress the cell viability of the leukemia cell line U937. It appears that the use of engineered ADSCs could be useful for the treatment of hematological malignancies.