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Introduction to Cells, DNA, and Viruses
Published in Patricia G. Melloy, Viruses and Society, 2023
Cellular macromolecules are organized into compartments called organelles (like little organs) that have an organization allowing for the work of the cell to happen. So, like organs such as the heart and lungs that have a special role in the body, organelles have a special role inside the cell. Some examples of key cellular organelles include the nucleus (where DNA is housed), mitochondria (energy generation), and ribosomes (protein production). Except for the nucleolus residing in the nucleus, organelles are found in what is known as the cytoplasm or cytosol of the eukaryotic cell. The nucleus is an important organelle because it acts as the central control point for all the activities of the cell. The nucleus houses most of the cell’s DNA in the form of protein/DNA structures known as chromosomes that allow for condensation of the large amount of genetic material in each cell (Alberts et al. 2019). Cell division occurs in a process known as mitosis, in which the chromosomes are copied and separated equally between the two daughter cells. Later, we will talk about organelles that help move or traffic things around the cell, as well as into and out of the cell. Trafficking-related organelles include the endoplasmic reticulum, Golgi apparatus, and vesicles. Viruses can exploit the cellular trafficking network to move into and out of the cell.
Understanding the Interaction of Nanoparticles at the Cellular Interface
Published in D. Sakthi Kumar, Aswathy Ravindran Girija, Bionanotechnology in Cancer, 2023
The Golgi apparatus is a vital organelle as it plays a crucial role in protein processing. The organelle functions as an integral unit in a cell because of its shape. Any anomaly in the condition of the Golgi apparatus is known to cause abnormalities in the cell. Once inside the cell, NPs interact with various cell organelles, one of which is the Golgi apparatus. Ma et al. have conducted a study to identify the effects of gold NPs on the Golgi apparatus [54]. Interestingly, gold NPs (50 nm) in normal rat kidney epithelial cells (NRK Line) have disrupted the calcium level inside the cell leading to the endoplasmic reticulum (ER) stress. The calcium ion concentration in cell organelles plays a crucial role in maintaining organelle function and structure. Similarly, the Golgi apparatus’s configuration changed from the familiar ribbon-like design into mini stacks, which were not linked or aligned. To study the Golgi apparatus’s functioning, mannosidase II and Galactosyltransferase were selected, and cells treated with gold NPs showed a significant decrease in their production. Cluster analysis of genes expressed in control and section treated with gold NPs showed substantial expression patterns. There is a change in the regulation of integrin-mediated cellular adhesion, which plays a crucial role in cell-extracellular matrix adhesion.
Neuromuscular Physiology
Published in Michael H. Stone, Timothy J. Suchomel, W. Guy Hornsby, John P. Wagle, Aaron J. Cunanan, Strength and Conditioning in Sports, 2023
Michael H. Stone, Timothy J. Suchomel, W. Guy Hornsby, John P. Wagle, Aaron J. Cunanan
The cytoskeletal system consists of a protein network that strengthens and stabilizes various structures within the cell (125, 127). Proteins forming the cytoskeleton, such as dystrophin, actin, and spectrin, strengthen and support the sarcolemma and prevent tearing during contraction. Near the Z-disc, the proteins desmin, synemin, and vimentin encase the myofibrils and bind them together. The cytoskeleton also supports and positions other organelles such as nuclei and mitochondria (Figure 1.7).
Bazi Bushen capsule attenuates cognitive deficits by inhibiting microglia activation and cellular senescence
Published in Pharmaceutical Biology, 2022
Chuanyuan Ji, Cong Wei, Mengnan Li, Shuang Shen, Shixiong Zhang, Yunlong Hou, Yiling Wu
Neurons are the main components of brain tissue, which exchange information by receiving, integrating, conducting and outputting information. Nissl bodies are plaque-like or granular substances present in neurons. They are composed of a large number of rough endoplasmic reticulum and free ribosomes, which mainly synthesize proteins required for the renewal of organelles. Nissl bodies can be used as a marker of neuronal functional status. The Nissl bodies undergo decrease, loss and dissolution in an injured neuron. Nissl bodies can increase and return to normal levels in the recovery from neuronal injury (Kaufmann et al. 2012). The current study showed that BZBS can protect against neuronal damage and ameliorate the cognitive deficits in d-gal-induced ageing mice (Figure 4(C,D)).
Progress in tumour-targeted drug delivery based on cell-penetrating peptides
Published in Journal of Drug Targeting, 2022
Xinru Kong, Jiangkang Xu, Xiaoye Yang, Yujia Zhai, Jianbo Ji, Guangxi Zhai
The nucleus is the control centre of the cell and is one of the most targeted organelles in cancer nanomedicine. Nuclear localised CPPs are usually composed of a nuclear localisation sequence (NLS) and a transmembrane sequence. Common NLSs include TAT, SV40 large T antigens, and SRY proteins [84]. Zhang et al. [10] reported an NF-κB inhibitor peptide, CB5005, which consists of 21 amino acids and can be divided into two cascade fragments: the membrane permeation sequence (CB5005M), and the NLS (CB5005N) (Figure 5(A)). TAT seems to have nuclear targeting ability. Pang et al. [85] improved PTT treatment by delivering iron oxide nanoparticles (IONPs) to the nucleus, using TAT to functionalise IONPs to achieve effective nuclear targeting, and using fluorescent dyes for real-time tracking. Approximately 122 µg iron per milligram protein accumulated in the nucleus, which was 45 times higher than that of unmodified TAT.
Analysis of the acrylamide in breads and evaluation of mitochondrial/lysosomal protective agents to reduce its toxicity in vitro model
Published in Toxin Reviews, 2022
Ahmad Salimi, Rafat Pashaei, Shahab Bohlooli, Mehrdad Vaghar-Moussavi, Jalal Pourahmad
Lysosomes are the acidic organelles for recycling defective cellular and degradation materials and enable an optimal physicochemical environment for enzymatic activities, which need to be controlled (Pascua-Maestro et al.2017). Presently, documented functions like immune response, cell death, plasma membrane repair, energy, and nutrient sensing and secretion, reveal the importance of lysosomes in controlling fine decisions in the life of a cell (Xu and Ren 2015). Environmental tensions such as oxidative damages and ROS generation can damage lysosomal membranes and lead to membrane permeabilization. Usual function of lysosomes depends on intraluminal acidic pH and needs constant membrane-dependent proton gradients (Johansson et al.2010). Chloroquine agent prevents endosomal acidification. This drug accumulates inside the acidic parts of the cell, including lysosomes and endosomes. This accumulation leads to inhibition of lysosomal enzymes that require an acidic pH, and prevents fusion of endosomes and lysosomes. Moreover, chloroquine inhibits autophagy as it raises the lysosomal pH, which leads to inhibition of both fusion of autophagosome with lysosome and lysosomal protein degradation (Choi et al.2013). Our results showed that acrylamide induces lysosomal damages in human lymphocytes that their damage is prevented by chloroquine.