المؤلفون: Sofie Snoeck, Chiara Guidi, Marjan De Mey

المصدر: Microbial Cell Factories, Vol 23, Iss 1, Pp 1-19 (2024)

مصطلحات موضوعية: Stress response mechanisms, Escherichia coli, Protein expression, Metabolic engineering, Microbiology, QR1-502

الوصف: Abstract Background Engineering bacterial strains to redirect the metabolism towards the production of a specific product has enabled the development of industrial biotechnology. However, rewiring the metabolism can have severe implications for a microorganism, rendering cells with stress symptoms such as a decreased growth rate, impaired protein synthesis, genetic instability and an aberrant cell size. On an industrial scale, this is reflected in processes that are not economically viable. Main text In literature, most stress symptoms are attributed to “metabolic burden”, however the actual triggers and stress mechanisms involved are poorly understood. Therefore, in this literature review, we aimed to get a better insight in how metabolic engineering affects Escherichia coli and link the observed stress symptoms to its cause. Understanding the possible implications that chosen engineering strategies have, will help to guide the reader towards optimising the envisioned process more efficiently. Conclusion This review addresses the gap in literature and discusses the triggers and effects of stress mechanisms that can be activated when (over)expressing (heterologous) proteins in Escherichia coli. It uncovers that the activation of the different stress mechanisms is complex and that many are interconnected. The reader is shown that care has to be taken when (over)expressing (heterologous) proteins as the cell’s metabolism is tightly regulated.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/1475-2859Test

الوصول الحر: https://doaj.org/article/bd7bbca9e2fc4da48b95295eba7beecaTest

المؤلفون: Yuye Zheng, Yiwei Cai, Tong Sun, Guiying Li, Taicheng An

المصدر: Environment International, Vol 187, Iss , Pp 108729- (2024)

مصطلحات موضوعية: Antibiotic resistance, L-form bacteria, Response mechanisms, Cell wall deficient, Gram-negative bacteria, Gram-positive bacteria, Environmental sciences, GE1-350

الوصف: Due to the specific action on bacterial cell wall, β-lactam antibiotics have gained widespread usage as they exhibit a high degree of specificity in targeting bacteria, but causing minimal toxicity to host cells. Under antibiotic pressure, bacteria may opt to shed their cell walls and transform into L-form state as a means to evade the antibiotic effects. In this study, we explored and identified diverse optimal conditions for both Gram-negative bacteria (E. coli DH5α (CTX)) and Gram-positive bacteria (B. subtilis ATCC6633), which were induced to L-form bacteria using lysozyme (0.5 ppm) and meropenem (64 ppm). Notably, when bacteria transformed into L-form state, both bacterial strains showed varying degrees of increased resistance to antibiotics polymyxin E, meropenem, rifampicin, and tetracycline. E. coli DH5α (CTX) exhibited the most significant enhancement in resistance to tetracycline, with a 128-fold increase, while B. subtilis ATCC6633 showed a 32-fold increase in resistance to tetracycline and polymyxin E. Furthermore, L-form bacteria maintained their normal metabolic activity, combined with enhanced oxidative stress, served as an adaptive strategy promoting the sustained survival of L-form bacteria. This study provided a theoretical basis for comprehending antibiotic resistance mechanisms, developing innovative treatment strategies, and confronting global antibiotic resistance challenges.

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S0160412024003155Test; https://doaj.org/toc/0160-4120Test

الوصول الحر: https://doaj.org/article/a45a7aa0d0704a72869f12f69518996bTest

المؤلفون: Jia Guo, Hanlu Zhang, Yixuan Zhao, Xiaoxu Hao, Yu Liu, Suhong Li, Rina Wu

المصدر: Toxins, Vol 16, Iss 6, p 256 (2024)

مصطلحات موضوعية: aflatoxin B1, Bacillus halotolerans, biodegradation, thermostable extracellular proteins, response mechanisms, Medicine

الوصف: Aflatoxin B1 (AFB1) contamination is a food safety issue threatening human health globally. Biodegradation is an effective method for overcoming this problem, and many microorganisms have been identified as AFB1-degrading strains. However, the response mechanisms of these microbes to AFB1 remain unclear. More degrading enzymes, especially of new types, need to be discovered. In this study, a novel AFB1-degrading strain, DDC-4, was isolated using coumarin as the sole carbon source. This strain was identified as Bacillus halotolerans through physiological, biochemical, and molecular methods. The strain’s degradation activity was predominantly attributable to thermostable extracellular proteins (degradation rate remained approximately 80% at 90 °C) and was augmented by Cu2+ (95.45% AFB1 was degraded at 48 h). Alpha/beta hydrolase (arylesterase) was selected as candidate AFB1-degrading enzymes for the first time as a gene encoding this enzyme was highly expressed in the presence of AFB1. Moreover, AFB1 inhibited many genes involved in the nucleotide synthesis of strain DDC-4, which is possibly the partial molecular mechanism of AFB1’s toxicity to microorganisms. To survive under this stress, sporulation-related genes were induced in the strain. Altogether, our study identified a novel AFB1-degrading strain and explained its response mechanisms to AFB1, thereby providing new insights for AFB1 biodegradation.

وصف الملف: electronic resource

العلاقة: https://www.mdpi.com/2072-6651/16/6/256Test; https://doaj.org/toc/2072-6651Test

الوصول الحر: https://doaj.org/article/cd82aeaf531d449498ae79c31ab15ea0Test

المؤلفون: Snoeck, Sofie, Guidi, Chiara, De Mey, Marjan

المصدر: MICROBIAL CELL FACTORIES ; ISSN: 1475-2859

مصطلحات موضوعية: Biology and Life Sciences, Medicine and Health Sciences, Metabolic engineering, Protein expression, Escherichia coli, Stress response mechanisms

الوصف: Background Engineering bacterial strains to redirect the metabolism towards the production of a specific product has enabled the development of industrial biotechnology. However, rewiring the metabolism can have severe implications for a microorganism, rendering cells with stress symptoms such as a decreased growth rate, impaired protein synthesis, genetic instability and an aberrant cell size. On an industrial scale, this is reflected in processes that are not economically viable. Main text In literature, most stress symptoms are attributed to "metabolic burden", however the actual triggers and stress mechanisms involved are poorly understood. Therefore, in this literature review, we aimed to get a better insight in how metabolic engineering affects Escherichia coli and link the observed stress symptoms to its cause. Understanding the possible implications that chosen engineering strategies have, will help to guide the reader towards optimising the envisioned process more efficiently. Conclusion This review addresses the gap in literature and discusses the triggers and effects of stress mechanisms that can be activated when (over)expressing (heterologous) proteins in Escherichia coli. It uncovers that the activation of the different stress mechanisms is complex and that many are interconnected. The reader is shown that care has to be taken when (over)expressing (heterologous) proteins as the cell's metabolism is tightly regulated.

وصف الملف: application/pdf

العلاقة: https://biblio.ugent.be/publication/01HX9YXZBNKHBN7GNDZFZ7DRYSTest; http://hdl.handle.net/1854/LU-01HX9YXZBNKHBN7GNDZFZ7DRYSTest; http://doi.org/10.1186/s12934-024-02370-9Test; https://biblio.ugent.be/publication/01HX9YXZBNKHBN7GNDZFZ7DRYS/file/01HX9YZHWJRMNAMYMQM0G1X4KRTest

الإتاحة: https://doi.org/10.1186/s12934-024-02370-9Test
https://biblio.ugent.be/publication/01HX9YXZBNKHBN7GNDZFZ7DRYSTest
http://hdl.handle.net/1854/LU-01HX9YXZBNKHBN7GNDZFZ7DRYSTest
https://biblio.ugent.be/publication/01HX9YXZBNKHBN7GNDZFZ7DRYS/file/01HX9YZHWJRMNAMYMQM0G1X4KRTest

المؤلفون: Marisa Fonseca-Carvalho, Gabriela Veríssimo, Mariana Lopes, Daniela Ferreira, Sandra Louzada, Raquel Chaves

المصدر: Biomolecules, Vol 14, Iss 1, p 124 (2024)

مصطلحات موضوعية: cellular stress, satellite DNA, satellite non-coding RNAs, stress-response mechanisms, Microbiology, QR1-502

الوصف: Organisms are often subjected to conditions that promote cellular stress. Cell responses to stress include the activation of pathways to defend against and recover from the stress, or the initiation of programmed cell death to eliminate the damaged cells. One of the processes that can be triggered under stress is the transcription and variation in the number of copies of satellite DNA sequences (satDNA), which are involved in response mechanisms. Satellite DNAs are highly repetitive tandem sequences, mainly located in the centromeric and pericentromeric regions of eukaryotic chromosomes, where they form the constitutive heterochromatin. Satellite non-coding RNAs (satncRNAs) are important regulators of cell processes, and their deregulation has been associated with disease. Also, these transcripts have been associated with stress-response mechanisms in varied eukaryotic species. This review intends to explore the role of satncRNAs when cells are subjected to adverse conditions. Studying satDNA transcription under various stress conditions and deepening our understanding of where and how these sequences are involved could be a key factor in uncovering important facts about the functions of these sequences.

العلاقة: https://www.mdpi.com/2218-273X/14/1/124Test; https://doaj.org/toc/2218-273XTest; https://doaj.org/article/42923c17f58244ecbd0c1437f08c752fTest

الإتاحة: https://doi.org/10.3390/biom14010124Test
https://doaj.org/article/42923c17f58244ecbd0c1437f08c752fTest

المؤلفون: Sankaram, Mosa, Roopesh, Ms, Rasetti, Sasank, Nishat, Nourin

المصدر: Global Mainstream Journal of Business, Economics, Development & Project Management; Vol. 3 No. 05 (2024): Global Mainstream Journal of Business, Economics, Development & Project Management; 1-14 ; 2998-3746

مصطلحات موضوعية: Artificial Intelligence, Cybersecurity, Threat Detection, Response Mechanisms, Machine Learning, Deep Learning, Network Security, Intrusion Detection Systems

الوصف: This literature review explores the transformative impact of artificial intelligence (AI) on enhancing cybersecurity measures across various domains. The study systematically examines the integration of AI in Intrusion Detection Systems (IDS), malware detection, phishing detection, threat intelligence, network security, and endpoint protection. Key findings reveal that AI-driven techniques significantly outperform traditional methods, particularly in real-time threat detection, accuracy, and adaptive response capabilities. Network-based IDS benefit from supervised and unsupervised learning algorithms, improving the identification of malicious network traffic and novel attack patterns. In malware detection, AI-enhanced static and dynamic analysis methods surpass signature-based approaches by detecting previously unknown malware and complex behaviors. Phishing detection has seen substantial improvements with AI applications in email filtering and URL analysis, reducing phishing incidents despite challenges like false positives. AI's role in threat intelligence is critical, automating data analysis to uncover hidden threats and employing predictive analytics to anticipate and mitigate cyber attacks. AI techniques in network security and endpoint protection enhance real-time monitoring and authentication processes, providing robust defenses against cyber intrusions. Despite these advancements, challenges such as handling high data volumes and the need for continuous learning to adapt to emerging threats remain. This review underscores the significant advancements, practical implementations, and ongoing challenges of leveraging AI in cybersecurity, highlighting its potential to fortify digital defenses and address the complexities of contemporary cyber threats.

وصف الملف: application/pdf

العلاقة: https://www.globalmainstreamjournal.com/index.php/BEDPM/article/view/180/140Test; https://www.globalmainstreamjournal.com/index.php/BEDPM/article/view/180Test

الإتاحة: https://doi.org/10.62304/jbedpm.v3i05.180Test
https://www.globalmainstreamjournal.com/index.php/BEDPM/article/view/180Test

المؤلفون: Lu F, Kato J, Toramaru T, Zhang M, Morisaki H

المصدر: Journal of Pain Research, Vol Volume 16, Pp 573-587 (2023)

مصطلحات موضوعية: complex regional pain syndrome, hypoxic response mechanisms, postoperative pain, sudomotor dysfunction, sympathetic denervation., Medicine (General), R5-920

الوصف: Fanglin Lu,1,2 Jungo Kato,2 Tomoko Toramaru,2 Mengting Zhang,1,2 Hiroshi Morisaki2 1Keio University Graduate School of Medicine Doctoral Programs, Tokyo, Japan; 2Department of Anesthesiology, Keio University School of Medicine, Tokyo, JapanCorrespondence: Jungo Kato, Department of Anesthesiology, Keio University School of Medicine, 35 Shinanoamchi, Shinjuku-ku, Tokyo, 160-8582, Japan, Tel +81-3-3353-1211, Fax +81-3-3356-8439, Email jungo-k.a2@keio.jpPurpose: The involvement of hypoxic response mechanisms in local functional impairments in surgical wounds is unclear. In the present study, we characterized tissue hypoxia in surgical wounds and investigated the role of pharmacological ischemic conditioning (PIC) using roxadustat, an oral prolyl hydroxylase domain enzyme inhibitor, in postoperative local functional impairments in a murine model of deep hind paw incision.Methods: Male BALB/cAJcl mice aged 9– 13 weeks were used in all experiments. Plantar skins of mice that underwent surgical incision were subjected to immunohistochemistry to localise tissue hypoxia. Pain-like behaviours and sudomotor function were compared between mice treated with 6-week perioperative PIC and control mice. The effects of PIC were examined in vitro by immunocytochemistry using sympathetically differentiated PC12 cells and in vivo by immunohistochemistry using plantar skins collected on postoperative day 21.Results: Prominent tissue hypoxia was detected within axons in the nerve bundles underneath surgical wounds. Six-week perioperative PIC using roxadustat failed to ease spontaneous pain-like behaviors; however, it mitigated local sudomotor impairment postoperatively. Upregulation of sympathetic innervation to the eccrine glands was observed in the PIC-treated skins collected on postoperative day 21, in accordance with the in vitro study wherein roxadustat promoted neurite growth of sympathetically differentiated PC12 cells.Conclusion: This study suggests that tissue hypoxia is involved in the pathogenesis of local sudomotor dysfunction associated with surgical trauma. Targeting the hypoxic response mechanisms with PIC may be of therapeutic potential in postsurgical local sympathetic impairments that can be present in complex regional pain syndrome.Keywords: complex regional pain syndrome, hypoxic response mechanisms, postoperative pain, sudomotor dysfunction, sympathetic denervation

وصف الملف: electronic resource

العلاقة: https://www.dovepress.com/pharmacological-ischemic-conditioning-with-roxadustat-does-not-affect--peer-reviewed-fulltext-article-JPRTest; https://doaj.org/toc/1178-7090Test

الوصول الحر: https://doaj.org/article/c530a222ba3043149312e91ed87e1a30Test

المؤلفون: Junnan Xu, Ning Zhao, Xuemei Meng, Jun Li, Tong Zhang, Ruoyun Xu, Xinyuan Wei, Mingtao Fan

المصدر: Microbiology Spectrum, Vol 11, Iss 4 (2023)

مصطلحات موضوعية: Alicyclobacillus acidoterrestris, acid stress, transcriptomic analysis, metabolomic analysis, response mechanisms, pH homeostasis, Microbiology, QR1-502

الوصف: ABSTRACT Alicyclobacillus acidoterrestris, which has strong acidophilic and heat-resistant properties, can cause spoilage of pasteurized acidic juice. The current study determined the physiological performance of A. acidoterrestris under acidic stress (pH 3.0) for 1 h. Metabolomic analysis was carried out to investigate the metabolic responses of A. acidoterrestris to acid stress, and integrative analysis with transcriptome data was also performed. Acid stress inhibited the growth of A. acidoterrestris and altered its metabolic profiles. In total, 63 differential metabolites, mainly enriched in amino acid metabolism, nucleotide metabolism, and energy metabolism, were identified between acid-stressed cells and the control. Integrated transcriptomic and metabolomic analysis revealed that A. acidoterrestris maintains intracellular pH (pHi) homeostasis by enhancing amino acids decarboxylation, urea hydrolysis, and energy supply, which was verified using real-time quantitative PCR and pHi measurement. Additionally, two-component systems, ABC transporters, and unsaturated fatty acid synthesis also play crucial roles in resisting acid stress. Finally, a model of the responses of A. acidoterrestris to acid stress was proposed. IMPORTANCE Fruit juice spoilage caused by A. acidoterrestris contamination has become a major concern and challenge in the food industry, and this bacterium has been suggested as a target microbe in the design of the pasteurization process. However, the response mechanisms of A. acidoterrestris to acid stress still remain unknown. In this study, integrative transcriptomic, metabolomic, and physiological approaches were used to uncover the global responses of A. acidoterrestris to acid stress for the first time. The obtained results can provide new insights into the acid stress responses of A. acidoterrestris, which will point out future possible directions for the effective control and application of A. acidoterrestris.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2165-0497Test

الوصول الحر: https://doaj.org/article/cb2063b79e8846d19ddb0c92a69a7a92Test

المؤلفون: Yurong Liu, Xinming Zhang, Shan Lei, Yaru Wang, Peng Huang, Jing Lin

المصدر: Advanced Sensor Research, Vol 2, Iss 8, Pp n/a-n/a (2023)

مصطلحات موضوعية: activatable organic probes, chemical processes, in vivo pH‐detection, photoacoustic imaging, response mechanisms, Technology (General), T1-995, Science

الوصف: Abstract All life forms require pH homeostasis. The disorder of pH homeostasis is associated with many severe diseases, suggesting the significance of pH‐detection for theranostic diseases. Photoacoustic imaging (PAI) technology has piqued great research interests in spatiotemporal detection of pH in vivo due to its non‐invasiveness and non‐ionization, as well as the high resolution and deep tissue penetration. This mini‐review outlines the most recent advances in activatable organic PA probes for pH‐detection with respect to molecular design, response mechanisms, and their in vivo applications. The basic understanding of PA probes is clarified. The pH‐response mechanisms of the PA probes at the molecular level are particularly emphasized to elucidate the structural design strategies. Finally, the challenges and perspectives, mainly focusing on quantitative detection, are discussed. This review aims to pave the way for further exploration of responsive organic PA probes for in vivo pH‐detection.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2751-1219Test

الوصول الحر: https://doaj.org/article/1f89c55d40d24db194f5e944f0e97050Test

المؤلفون: Voisin, Jessica, Farina, Francesca, Naphade, Swati, Fontaine, Morgane, Tshilenge, Kizito-Tshitoko, Galicia Aguirre, Carlos, Lopez-Ramirez, Alejandro, Dancourt, Julia, Ginisty, Aurélie, Sasidharan Nair, Satish, Lakshika Madushani, Kuruwitage, Zhang, Ningzhe, Lejeune, François-Xavier, Verny, Marc, Campisi, Judith, Ellerby, Lisa M, Neri, Christian

المصدر: Aging cell. 19(11)

مصطلحات موضوعية: Neurons, Humans, Huntington Disease, Cyclin-Dependent Kinase Inhibitor p16, Neural Stem Cells, Forkhead Box Protein O3, neurodegenerative disease, neuronal differentiation, neuronal senescence, response mechanisms, temporal dynamics, Stem Cell Research, Brain Disorders, Neurosciences, Neurodegenerative, Huntington's Disease, Stem Cell Research - Nonembryonic - Non-Human, Rare Diseases, Aging, 1.1 Normal biological development and functioning, 2.1 Biological and endogenous factors, Neurological, Developmental Biology, Biological Sciences, Medical and Health Sciences

الوصف: Neurodegenerative diseases (ND) have been linked to the critical process in aging-cellular senescence. However, the temporal dynamics of cellular senescence in ND conditions is unresolved. Here, we show senescence features develop in human Huntington's disease (HD) neural stem cells (NSCs) and medium spiny neurons (MSNs), including the increase of p16INK4a , a key inducer of cellular senescence. We found that HD NSCs reprogram the transcriptional targets of FOXO3, a major cell survival factor able to repress cell senescence, antagonizing p16INK4a expression via the FOXO3 repression of the transcriptional modulator ETS2. Additionally, p16INK4a promotes cellular senescence features in human HD NSCs and MSNs. These findings suggest that cellular senescence may develop during neuronal differentiation in HD and that the FOXO3-ETS2-p16INK4a axis may be part of molecular responses aimed at mitigating this phenomenon. Our studies identify neuronal differentiation with accelerated aging of neural progenitors and neurons as an alteration that could be linked to NDs.

وصف الملف: application/pdf

الوصول الحر: https://escholarship.org/uc/item/6f59z2s1Test