The cell and tissues
Peate Ian, Dutton Helen in Acute Nursing Care, 2020
Lysosomes are small spherical organelles, surrounded by plasma membrane. They contain enzymes that are capable of degrading and breaking down all sorts of material from bacteria and toxins to worn-out organelles. They are therefore abundant in phagocytic cells (cells that engulf and destroy bacteria and cell debris in the inflammatory process), such as macrophages and neutrophils. These small structures create a safe area for the destruction of unwanted material within cells. The digestive environment is very acidic and requires energy in the form of ATP to pump hydrogen ions into these organelles. If the pump fails because of a lack of ATP, associated with poor oxygen supply, then the lysosomes do not function properly and the degradation process is inhibited, leading to a breakdown in cellular function.
The cell and tissues
Ian Peate, Helen Dutton in Acute Nursing Care, 2014
Lysosomes are small spherical organelles surround by plasma membrane. They contain enzymes that are capable of degrading and breaking down all sorts of material from bacteria and toxins to worn out organelles. They are therefore abundant in phagocytic cells (cells that engulf and destroy bacteria and cell debris in the inflammatory process) such as macrophages and neutrophils. These small structures create a safe area for the destruction of unwanted material within cells. The digestive environment is very acidic and requires energy in the form of ATP to pump hydrogen ions into these organelles. If the pump fails because of lack of ATP associated with poor oxygen supply then the lysosomes do not function properly and the degradation process is inhibited leading to a breakdown in cellular function.
Herbal Therapy for Cancer
Prakash Srinivasan Timiri Shanmugam in Understanding Cancer Therapies, 2018
Autophagy is one of the arenas that was implicated in recent anticancer strategies. It is the process by which cellular material is delivered to lysosomes for degradation and recycling. It is involved in cell growth, survival, development, and cell death. Autophagy plays dual roles in the formation and progression of cancer, including both suppressive and promotive roles. According to Thorburn et al., the roles of autophagy in cancer treatment are complicated by two important discoveries over the past few years. First, most (perhaps all) anticancer drugs, as well as ionizing radiation, affect autophagy. In most, but not all cases, these treatments increase autophagy in tumor cells. Second, autophagy affects the ability of tumor cells to die after drug treatment, but the effect of autophagy may be to promote or inhibit cell death (Thorburn et al. 2014). In an oral cancer model, EGCG treatment has been found to suppress proliferation of SSC-4 human oral squamous cell carcinoma (OSCC) cells in a dose- and time-dependent manner. Concomitantly, the activation of apoptosis and autophagy in response to EGCG exposure in SSC-4 cells was observed. Treatment with EGCG activates the cell death receptors, leading to activation of intrinsic apoptotic pathways. All of these results suggest that EGCG has excellent potential to become a therapeutic compound for patients with OSCC by inducing tumor cell death via apoptosis and autophagy (Irimie et al. 2015).
[12]aneN3-based multifunctional compounds as fluorescent probes and nucleic acids delivering agents
Published in Drug Delivery, 2020
Yong-Guang Gao, Shu-Yuan Huangfu, Suryaji Patil, Quan Tang, Wan Sun, Yu Li, Zhong-Lin Lu, Airong Qian
It is well known that lysosome is one of important organelles in eukaryotic cells. It plays a key role in the degradation of macromolecules and cell components. The pH value in lysosomes ranges from 4.0 to 6.0, while the cytoplasm is about 7.2. The 1-Cu complexes exhibit strong fluorescence emission under acid conditions, while almost no fluorescence emission under neutral conditions, which make us believe that 1-Cu complexes can be used for lysosome imaging. In order to confirm above idea, lysosome imaging experiment was carried out in HeLa cells. Lyso-Tracker Red, a commercially available lysosome specific staining probe, was used to co-stain HeLa cells with 1-Cu complexes. HeLa cells were firstly incubated with 1-Cu complexes for 30 min, and then the medium was replaced with fresh medium containing Lyso-Tracker Red and incubated for another 30 min. As shown in Figure 5, the green emission of 1a-Cu, 1b-Cu, 1c-Cu, and 1d-Cu (Figure 5(A1–D1)) and the red emission of Lyso-Tracker Red (Figure 5(A2–D2)) are nearly overlapping (Figure 5(A3–D3)). The correlation coefficient of overlap between green and red channel has been analyzed by IPP software. The Overlap coefficients of 1a–1e with Lyso-Tracker Red are 0.93, 0.85, 0.88, 0.95 and 0.81, respectively. These results indicate that the 1-Cu complexes can be applied to fluorescence probes lysosome imaging.
Subcellular drug distribution: mechanisms and roles in drug efficacy, toxicity, resistance, and targeted delivery
Published in Drug Metabolism Reviews, 2018
Qiao Li, Ting Zhou, Fei Wu, Na Li, Rui Wang, Qing Zhao, Yue-Ming Ma, Ji-Quan Zhang, Bing-Liang Ma
Lysosomes are important organelles that are composed of a monolayer cystic structure and contain a variety of hydrolytic enzymes. They are associated with many cellular functions including degradation, secretion, and signaling (Settembre et al. 2013). Moreover, they play important roles in the disposition, efficacy, and side effects of drugs through the degradation of membrane drug transporters or by decreasing transporter activity. For example, organic anion transporting polypeptide (OATP) 1B1 mediates the hepatic uptake of drugs from the systemic circulation, including cholesterol-lowering statins. Increased lysosomal degradation of membrane OATP1B1 proteins or decreased OATP1B1 transport activity due to lysosomotropic drugs may lead to increased systemic exposure of statins and statin-induced myopathy (Alam et al. 2016).
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.