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All Topic Review Biography
Topic Review
Stress Accelerates Tumor Progression via Sympathetic Nervous System
The sympathetic nervous system (SNS) originates in the ventral brainstem, where sympathetic premotor neurons are found. They are found predominantly in the rostral ventrolateral medulla (RVLM) and in the rostral ventromedial medulla (RVMM). These neurons project to the intermediolateral nucleus (IML, also known as the sympathetic preganglionic nucleus), which then projects to the dorsal root ganglia (DRG) for terminal output to peripheral organs which control heart rate, blood pressure, respiration, glycemia, vigilance and other physiological responses. When negative emotions are induced under chronic stress, the sympathetic nervous system is continuously activated and increases the release of catecholamines (such as epinephrine and norepinephrine). In a spontaneous colon tumor model, ablation of sympathetic premotor neurons in APCmin/+ mice reduces the number of polyps in the mouse intestine. Sympathetic denervation also leads to decreased tumorigenesis in a spontaneous prostate tumor mouse model. These results suggest that loss of SNS function may slow tumorigenesis.
  • 451
  • 01 Nov 2022
Topic Review
Streptavidin
Streptavidin /ˌstrɛpˈtævɪdɪn/ is a 52.8 kDa protein purified from the bacterium Streptomyces avidinii. Streptavidin homo-tetramers have an extraordinarily high affinity for biotin (also known as vitamin B7 or vitamin H). With a dissociation constant (Kd) on the order of ≈10−14 mol/L, the binding of biotin to streptavidin is one of the strongest non-covalent interactions known in nature. Streptavidin is used extensively in molecular biology and bionanotechnology due to the streptavidin-biotin complex's resistance to organic solvents, denaturants (e.g. guanidinium chloride), detergents (e.g. SDS, Triton), proteolytic enzymes, and extremes of temperature and pH.
  • 1.4K
  • 25 Oct 2022
Topic Review
Store-Operated Calcium Entry in Cancer Stem Cells
Store-Operated Calcium Entry (SOCE), a major mechanism for Ca2+influx from the extracellular medium into excitable and non-excitable cells, is physiologically triggered by the activation of phospholipase C (PLC) and the production of IP3, which subsequently leads to the release of Ca2+from intracellular stores, mainly the ER, resulting in the activation of store-operated calcium channels in the plasma membrane and a rapid increase in cytosolic Ca2+concentration. SOCE is an extremely complex biological mechanism, with high dependency on the pattern of expression of its components-STIMs, Orai, and TRPC proteins- and its modulators in each cell type. Since the last decades of the 20th century, several studies, both in vivo and in vitro, have reported that an altered expression pattern of the proteins that mediate SOCE leads to unbalanced Ca2+homeostasis, which might contribute to tumor development, poor prognosis, and chemotherapeutic drug resistance.
  • 436
  • 29 Apr 2022
Topic Review
Stimulator of Interferon Genes (STING)
The stimulator of interferon genes (STING) is an adaptor protein involved in the activation of IFN-β and many other genes associated with the immune response activation in vertebrates. STING induction has gained attention from different angles such as the potential to trigger an early immune response against different signs of infection and cell damage, or to be used as an adjuvant in cancer immune treatments. Pharmacological control of aberrant STING activation can be used to mitigate the pathology of some autoimmune diseases. The STING structure has a well-defined ligand binding site that can harbor natural ligands such as specific purine cyclic di-nucleotides (CDN). In addition to a canonical stimulation by CDNs, other non-canonical stimuli have also been described, but the exact mechanism of some of them has not been well defined.
  • 445
  • 31 May 2023
Topic Review
Sterol Hormone 20-Hydroxyecdysone Biosynthesis
20E (20-Hydroxyecdysone) is a central steroid hormone that orchestrates developmental changes and metamorphosis in arthropods. PCD (Programmed cell death), including apoptosis, necrosis, efferocytosis, pyroptosis, ferroptosis, and autophagy, plays a crucial role in regulated cell elimination, which is vital for cells’ development and tissue homeostasis.
  • 147
  • 22 Nov 2023
Topic Review
Stemness and Apoptosis
Stemness and apoptosis may highlight the dichotomy between regeneration and demise in the complex pathway proceeding from ontogenesis to the end of life. In the last few years, the concept has emerged that the same microRNAs (miRNAs) can be concurrently implicated in both apoptosis-related mechanisms and cell differentiation. Whether the differentiation process gives rise to the architecture of brain areas, any long-lasting perturbation of miRNA expression can be related to the occurrence of neurodevelopmental/neuropathological conditions. Moreover, as a consequence of neural stem cell (NSC) transformation to cancer stem cells (CSCs), the fine modulation of distinct miRNAs becomes necessary. This event implies controlling the expression of pro/anti-apoptotic target genes, which is crucial for the management of neural/neural crest-derived CSCs in brain tumors, neuroblastoma, and melanoma.
  • 597
  • 20 Apr 2023
Topic Review
Stem-Cell-Based Therapy in Alzheimer’s Disease
Stem cells are a versatile source for cell therapy. Their use is particularly significant for the treatment of neurological disorders for which no definitive conventional medical treatment is available. Neurological disorders are of diverse etiology and pathogenesis. Alzheimer’s disease (AD) is caused by abnormal protein deposits, leading to progressive dementia.
  • 419
  • 15 Nov 2022
Topic Review
Stem Cells Radiation-Induced Regenerative Response
Radiotherapy is involved in the treatment of many cancers, but damage induced to the surrounding normal tissue is often inevitable. Evidence suggests that the maintenance of homeostasis and regeneration of normal tissues is driven by specific adult tissue stem/progenitor cells. These tasks involve the input from several signaling pathways. Irradiation also targets these stem/progenitor cells, triggering a cellular response aimed at achieving tissue regeneration.  
  • 489
  • 03 Mar 2021
Topic Review
Stem Cells and the Endometrium
Adult stem cells (ASCs) were long suspected to exist in the endometrium. Indeed, several types of endometrial ASCs were identified in rodents and humans through diverse isolation and characterization techniques. Putative stromal and epithelial stem cell niches were identified in murine models using label-retention techniques. In humans, functional methods (clonogenicity, long-term culture, and multi-lineage differentiation assays) and stem cell markers (CD146, SUSD2/W5C5, LGR5, NTPDase2, SSEA-1, or N-cadherin) facilitated the identification of three main types of endogenous endometrial ASCs: stromal, epithelial progenitor, and endothelial stem cells. Further, exogenous populations of stem cells derived from bone marrow may act as key effectors of the endometrial ASC niche.
  • 535
  • 29 Apr 2021
Topic Review
Stem Cells
It is now well accepted that the human body contains adult stem cells or in other words post-natal stem cells that are capable of differentiating into other tissues and can regenerate or repair damaged tissues. Over the last decades, stem cell hypothesis, the development of tissue deficits due to the inability of stem cells to replenish lost cells, has become a reality. Stem cells were in a way studied by radiobiologists well before it was proposed as a hypothesis. In fact, the initial theory of the development of radiation lesions’ “target cell theory” was based on radiation-induced cell loss. Target cell theory introduced by Puck and Marcus considers cell loss as the cardinal cause of radiation induced normal tissue damage or tumour ablation. In recent years, it has been shown that the process of development of radiation damage and the damage itself starts by molecular changes long before denudation of target cells. However, one cannot deny the fact that the ultimate lesions manifest as loss of functional cells. Most bodily tissues possess a pool of clonogenic cells that are mobilised in response to assaults such as trauma or radiation. Damage to the tissue is repaired by proliferation of clonogenic or tissue specific stem cells. Sterilisation of these clonogenic cells by radiation manifests as radiation damage. In mild cases as the damage is sensed, these clonogenic cells migrate to the site of damage, and together with local surviving clonogic cells, proliferate to repair the tissue. However, in severe cases of tissue repairs, there might not be enough surviving clonogenic cells as the site of damage or sufficient number of mobilised cells to reach the site and repair the damage. Thus, the damage gets established as a result of failure of endogenous stem cells to regenerate the damaged tissue.
  • 914
  • 31 Jan 2022
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