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Topic Review
Biography
Topic Review
Asbestos and Intrahepatic Cholangiocarcinoma
The link between asbestos exposure and the onset of thoracic malignancies is well established. However epidemiological studies have provided evidences that asbestos may be also involved in the development of gastrointestinal tumors, including intrahepatic cholangiocarcinoma (ICC). In line with this observation, asbestos fibers have been detected in the liver of patients with ICC. Although the exact mechanism still remains unknown, the presence of asbestos fibers in the liver could be explained in the light of their translocation pathway following ingestion/inhalation. In the liver, thin and long asbestos fibers could remain trapped in the smaller bile ducts, particularly in the stem cell niche of the canals of Hering, and exerting their carcinogenic effect for a long time, thus inducing hepatic stem/progenitor cells (HpSCs) malignant transformation. In this scenario, chronic liver damage induced by asbestos fibers over the years could be seen as a classic model of stem cell-derived carcinogenesis, where HpSC malignant transformation represents the first step of this process. This phenomenon could explain the recent epidemiological findings, where asbestos exposure seems mainly involved in ICC, rather than extrahepatic cholangiocarcinoma, development.
636
04 Jun 2021
Topic Review
Arteriovenous and Cavernous Malformations
Brain arteriovenous malformations (BAVMs) are predominantly congenital vascular disorders that may arise anywhere inside of the central nervous system. They are comprised of one or more arterial feeders supplying a vascular nidus, and one or more draining veins. The nidus itself represents the site where arterial blood is shunted directly into the venous system without an interpolating network of capillaries.
600
18 Jun 2021
Topic Review
Arsenic-Induced Carcinogenesis
Arsenic is a chemical element that is toxic, and long-term exposure to it causes cancers such as lung, skin, liver, and bladder cancers. Over 150 million people around the world are affected by arsenic exposure.
533
21 Sep 2022
Topic Review
ARHGAP11B
ARHGAP11B is a human-specific gene that likely played a crucial role in human neocortex evolution by inducing hallmarks of cortical expansion. In contrast to its ancestral paralog, ARHGAP11A, ARHGAP11B does not act as a Rho GTPase Activating Protein in the nucleus but is localized in mitochondria and increases glutaminolysis. This increase is a prerequisite for increased basal progenitor proliferation – one essential basis for cortical expansion.
618
28 May 2021
Topic Review
Arabidopsis LSH8 ABA Signaling
LSH is a family of transcription factors with diversified functions, the members of which, in turn, are named LSH1-LSH10. LIGHT-DEPENDENT SHORT HYPOCOTYLS 1 (LSH1 was first found in Arabidopsis in 2004, the overexpression of which can enhance the light response of Arabidopsis thaliana seedlings and show an obvious short hypocotyl phenotype. All members of the LSH family have a highly conserved Domain of Unknown Function 640 (DUF640) domain, which is also called the Arabidopsis LSH1 and Oryza G1 (ALOG) domain in the Pfam protein database.
578
03 Dec 2021
Topic Review
Arabidopsis HY2 NaCl Signaling during Seed Germination
PΦB is an open-chain tetrapyrrole chromophore, a critical synthetase for phytochromes to function as a light receptor to regulate plant growth and development. Arabidopsis HY2 encodes a key synthase of PΦB, which is a ferredoxin-dependent biliverdin reductase that catalyzes the reduction in the A-ring 2,3,31,32-diene system to produce an ethylidene group for assembly with apophytochromes.
470
03 Dec 2021
Topic Review
Aquaporins in Mesenchymal Stem Cells
Aquaporins (AQPs) are a family of membrane water channel proteins that control osmotically-driven water transport across cell membranes. Recent studies have focused on the assessment of fluid flux regulation in relation to the biological processes that maintain mesenchymal stem cell (MSC) physiology. In particular, AQPs seem to regulate MSC proliferation through rapid regulation of the cell volume. Furthermore, several reports have shown that AQPs play a crucial role in modulating MSC attachment to the extracellular matrix, their spread, and migration. This review aims to describe the recent findings on AQPs role in MSCs physiology taking into account their reflex for potential applicatio in regenerative medicine.
677
24 Dec 2020
Topic Review
Aquaporins and Female Reproductive System
Aquaporins constitute a group of water channel proteins located in numerous cell types. These are pore-forming transmembrane proteins, which mediate the specific passage of water molecules through membranes. It is well-known that water homeostasis plays a crucial role in different reproductive processes, e.g., oocyte transport, hormonal secretion, completion of successful fertilization, blastocyst formation, pregnancy, and birth. Further, aquaporins are involved in the process of spermatogenesis, and they have been reported to be involved during the storage of spermatozoa. It is noteworthy that aquaporins are relevant for the physiological function of specific parts in the female reproductive system.
1.4K
22 Dec 2020
Topic Review
Aquaporin Inhibitors
Aquaporins (AQPs) are water channel proteins that are essential to life, being expressed in all kingdoms. In humans, there are 13 AQPs, at least one of which is found in every organ system. The structural biology of the AQP family is well-established and many functions for AQPs have been reported in health and disease. AQP expression is linked to numerous pathologies including tumor metastasis, fluid dysregulation, and traumatic injury. The targeted modulation of AQPs therefore presents an opportunity to develop novel treatments for diverse conditions. Various techniques such as video microscopy, light scattering and fluorescence quenching have been used to test putative AQP inhibitors in both AQP-expressing mammalian cells and heterologous expression systems. The inherent variability within these methods has caused discrepancy and many molecules that are inhibitory in one experimental system (such as tetraethylammonium, acetazolamide, and anti-epileptic drugs) have no activity in others. Some heavy metal ions (that would not be suitable for therapeutic use) and the compound, TGN-020, have been shown to inhibit some AQPs. Clinical trials for neuromyelitis optica treatments using anti-AQP4 IgG are in progress. However, these antibodies have no effect on water transport. More research to standardize high-throughput assays is required to identify AQP modulators for which there is an urgent and unmet clinical need.
4.2K
06 Sep 2021
Topic Review
Aquaporin 4
Aquaporin-4, also known as AQP4, is a water channel protein encoded by the AQP4 gene in humans. AQP4 belongs to the aquaporin family of integral membrane proteins that conduct water through the cell membrane. A limited number of aquaporins are found within the central nervous system (CNS): AQP1, 3, 4, 5, 8, 9, and 11, but more exclusive representation of AQP1, 4, and 9 are found in the brain and spinal cord. AQP4 shows the largest presence in the cerebellum and spinal cord grey matter. In the CNS, AQP4 is the most prevalent aquaporin channel, specifically located at the perimicrovessel astrocyte foot processes, glia limitans, and ependyma. In addition, this channel is commonly found facilitating water movement near cerebrospinal fluid and vasculature. Aquaporin-4 was first identified in 1986. It was the first evidence of the existence of water transport channels. The method that was used to discover the existence of the transport channels was through knockout experiments. With this technique they were able to show the significant role of AQP4 in CNS injuries and brain water imbalances. In 1994 the channel was successfully cloned and initially named Mercury-Insensitive Water Channel.
333
12 Oct 2022
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