Gateways of Pathogenic Bacterial Entry into Host Cells—Salmonella
K. Balamurugan, U. Prithika in Pocket Guide to Bacterial Infections, 2019
Caveolae, a 21–24 kDa integral membrane flask-shaped projection in the plasma membrane of endothelial cells, consist of three caveolin proteins named as caveolin 1, 2, and 3. Caveolin 1 and 2 are expressed together as a hetero oligomer in the plasma membrane, and caveolin 3 was expressed only in muscle tissue (Tang et al. 1996; Smart et al. 1999). Caveolin-1, a scaffolding protein expressed within the caveolar membrane, interacts with signaling proteins, such as epidermal growth factor receptor, G-proteins, Src-like kinases, Ha-Ras, insulin receptors, and integrins for regulating their activities (Smart et al. 1999). Caveolar endocytosis is an endocytosis mechanism including nutrients and pathogens in most of the prokaryotes and parasites via endoplasmic reticulum (ER) → golgi → cytoplasm not fuse with lysosome, letting helps the pathogens to escape from lysosomal degradation (Schnitzer et al. 1994).
Pulmonary Endothelium in Health and Viral Infections
Sunit K. Singh in Human Respiratory Viral Infections, 2014
The transcellular pathway is used by water and molecules with a Mr greater than 3 nm. The former uses channels across the lipid bilayer formed by proteins named aquaporins (Figure 4.1).16 Under normal conditions, the plasma proteins can also be transported through the endothelium via a fluid phase or using a receptor-mediated manner. Additionally, transcellular channels are often formed transiently in order to facilitate protein transportation, such as albumin by caveolae.17 The latter are vesicular carriers established as clusters in the membrane. The major component of caveolae is the protein caveolin-1. It plays an important role in caveolae formation, as well as molecule capture and transcytosis.1,17,18
Organic Chemicals
William J. Rea, Kalpana D. Patel in Reversibility of Chronic Disease and Hypersensitivity, Volume 4, 2017
Because inflammatory insulin resistance underpins much of the overt pathology associated with obesity and excess caloric intake, there is an adopted biased view of this physiology as a maladaptive response to overfeeding. Although the clinical consequences of obesity are undoubtedly grim, three lines of evidence call into question the current view of insulin resistance as an injurious response to mounting adiposity. First, numerous examples exist in which obesity and insulin resistance are divorced, including both lean, insulin-resistant (such as lipodystrophy and mice in which caveolin-1 has been knocked out454 and obese, insulin-sensitive states such as mice in which Fabp4 has been knocked out455) and cold-adapted mammals.456 Indeed, the relationship between insulin resistance and obesity in humans is similarly disjointed,457 with many obese individuals exhibiting better insulin sensitivity than expected for their adiposity.458 Moreover, many of the most widely used insulin-sensitizing pharmaceuticals are associated with an increase in adiposity rather than a decrease (e.g., thiazolidinedione treatment).459 This is why proper diet and a less polluted environment are so necessary for some people.
Ultrasonically controlled albumin-conjugated liposomes for breast cancer therapy
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2019
Nahid S. Awad, Vinod Paul, Mohammad H. Al-Sayah, Ghaleb A. Husseini
To internalize molecules from outside the cell, cells use a process called endocytosis. Via this process, cells can take up macromolecules, proteins and ligands [37]. The main endocytic routes are the clathrin-mediated endocytosis and the caveolae-mediated endocytosis. Caveolae are specialized membrane domains enriched in certain lipids cholesterol and proteins [38]. Caveolae can mediate endocytosis through a receptor-dependent or -independent fashion [39]. Caveolin-1 (Cav-1) is one of the main functional components of caveolae and plays an important role in caveolae formation. It expected that to induce tumour formation, rapid proliferation is required, and, therefore, downregulation of caveolin-1 expression may be necessary. The level of caveolin-1 is related to the invasiveness of the tumour [40]. According to Chatterjee et al. [41], nanoparticle conjugate of paclitaxel to HSA exhibits efficacy in pancreatic cancer, non–small cell lung cancer and breast cancer. The study found that Cav-1 protein levels correlated positively with cancer sensitivity to their albumin base nanoparticles and, therefore, caveolae are essential for the cancer uptake of albumin. In general, albumin binds to a cell-surface, 60-kDa glycoprotein (gp60) receptor (albondin). gp60 is localized in the caveolae and binds to caveolin-1 (an intracellular protein) with subsequent formation of the caveolae [42,43].
Pioglitazone restores phosphorylation of downregulated caveolin-1 in right ventricle of monocrotaline-induced pulmonary hypertension
Published in Clinical and Experimental Hypertension, 2022
Eva Malikova, Zuzana Kmecova, Gabriel Doka, Lenka Bies Pivackova, Peter Balis, Simona Trubacova, Eva Velasova, Peter Krenek, Jan Klimas
Caveolae are small invaginations of the surface of various cells such as endothelial, smooth muscle, epithelial cells, and fibroblasts affecting various physiological functions including cell surface signaling, endocytosis, and intracellular cholesterol transport. Caveolin-1 (cav-1) is one of the major constituents essential for caveolae formation. Cav-1 is expressed in two isoforms, caveolin-1α (cav-1α) and caveolin-1β (cav-1β), that are produced from two different mRNAs (5). Moreover, protein produced from cav-1α can be phosphorylated on tyrosine 14 (pTyr14cav-1) and compared to cav-1β has a slightly different subcellular distribution (6). In the heart, cav-1 is expressed in cardiac fibroblasts (7), numerically the most abundant cell type of heart (8). Cav-1 is also highly expressed in endothelial cells (9), which represent the major non-myocyte population (10). Phosphorylation of cav-1 on tyrosine 14 occurs as a response to cellular stress, hormone, and growth factor stimulation (11) and seems to inhibit fibroblast–myofibroblast transformation (12), which results in an increased extracellular matrix production (13).
Maca Root (Lepidium meyenii) Extract Increases the Expression of MMP-1 and Stimulates Migration of Triple-Negative Breast Cancer Cells
Published in Nutrition and Cancer, 2022
Daniela Bizinelli, Fernanda Flores Navarro, Flavia Lima Costa Faldoni
Caveolin-1 (Cav-1) is an integral membrane protein and a negative regulator in tumor metastasis possibly through the regulation of STAT-3 (51). In the literature, CAV1 has been proposed to be a tumor suppressor or a promoter depending on the subtypes and stages of cancers (52, 53). Overexpression of CAV1 suppressed migration in multiple cancer cell lines including MDA-MB-231 (52), and induced programmed cell death in these triple-negative cells (54). In general, BC presents a low expression of CAV1 compared to normal tissues. However, studies have suggested that CAV1 is an oncogene in basal-like/TNBC development, conferring drug-resistance, and leading cells to the apoptosis process when downregulated (46, 54, 55). Although our analysis on TCGA data showed that TNBC present a significantly lower expression of CAV1 compared with normal tissue, we did not assess protein expression. As maca root treatment has further reduced CAV1 expression, we suggest that this gene may have a role in the migration activity of L. meyenii.
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