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History of Asphyxia-related Deaths
Published in Burkhard Madea, Asphyxiation, Suffocation,and Neck Pressure Deaths, 2020
The working group of Kondo (see also Chapter 15) investigated the suitability of the expression of aquaporin-3 and aquaporin-1 as vitality markers of strangulation marks (Ishida et al. 2018). Aquaporins are membrane water channels that play critical roles in controlling the water contents of cells. They are expressed in many epithelia and endothelia that can regulate osmolality throughout the body. Aquaporin-1 is expressed in vascular endothelial cells throughout the body, including the skin. Epidermal aquaporin-3 is increased in a cutaneous burn wound. A total of 24 neck compression marks by ligatures were investigated. After immunostaining, a total of ten high power fields were selected randomly. Antemortem neck compression enhanced aquaporin-3 expression in the keratinocytes. These results have been confirmed by this author's own working group (Figure 1.40). Aquaporin-3 might be useful as a marker of all kinds of antemortem skin injuries.
Mechanism of Action of Isotretinoin
Published in Ayse Serap Karadag, Berna Aksoy, Lawrence Charles Parish, Retinoids in Dermatology, 2019
Isotretinoin treatment consistently induces mucocutaneous side effects by exhibiting dry skin with increased transepidermal water loss, often leading to retinoid dermatitis (93,94). Aquaporin 3 (AQP3) is an aquaglyceroporin which transports water, glycerol, and small solutes across the plasma membrane (95). Elevated expression level of AQP3 results in impaired barrier integrity and increased pro-inflammatory cytokine production, mimicking the pathologic conditions in Notch-deficient mice and in atopic dermatitis (96).
Endocrine physiology
Published in Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal, Principles of Physiology for the Anaesthetist, 2015
Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal
ADH controls the reabsorption of water by kidneys and constricts arterioles. Two vasopressin receptors have been identified: one (V1) found in vascular smooth muscle that mediates vasoconstriction, and another (V2) found in the distal tubules and collecting ducts of the kidney that mediates antidiuretic effects. The major action of ADH is an increase in water permeability of the apical membrane of the principal cells of the cortical and medullary collecting duct (Figure 11.9). ADH binds to the V2 receptor, a G protein– coupled receptor, located at the basolateral membrane of the aforementioned cells and increases cAMP and protein phosphorylation in the principal cells of renal tubules. Protein kinase A phosphorylates aquaporin 2 and inserts these pores into the luminal cell membrane and increases the permeability of epithelium at the lumen. Water reabsorbed through these aquaporin 2 channels leaves the cells through aquaporin 3 and 4 channels located in the basolateral membrane of the principal cells. This leads to a decreased volume of urine with increased osmolarity. ADH also reduces renal medullary blood flow.
Development of a Novel In Vitro Immuno-Competent Model of Dry Eye Disease and Its Use to Evaluate the Efficacy of an Ocular Surface Modulator
Published in Ocular Immunology and Inflammation, 2022
Marisa Meloni, Francesco Carriero, Laura Ceriotti, Stefano Barabino
A multiple endpoint approach has been adopted, including the evaluation of transcriptional activity of specific gene signatures, such as aquaporin 3 (AQP-3) for its crucial role in water channel properties modification in DED, Toll-like receptor 4 (TLR4), which is directly involved in innate immunity response and tumor necrosis factor α (TNF-α) as a biomarker of inflammatory pathway often associated to DED pathology as reported in Table 1. They have been studied at the mRNA level by qRT-PCR in order to have a quantitative approach, while the two biomarkers CD14 and CD86 have been investigated by immuno-staining (immunofluorescence). CD14 is a leucin rich-glycoprotein that functions as co-receptor of cytoplasmatic membrane: it is expressed by undifferentiated THP-1 monocytes and by corneal epithelial cells when interacting with THP-1.18 CD86 is a surface receptor expressed exclusively by dendritic cells or differentiated monocytic cells in APCs19 thus allowing to follow THP-1 dynamic response and to precisely figure out their differentiation. Thus, CD14 and CD86 can be used to discriminate between undifferentiated and differentiated THP-1 monocytes.
Frontiers of metal-coordinating drug design
Published in Expert Opinion on Drug Discovery, 2021
Giulia Palermo, Angelo Spinello, Aakash Saha, Alessandra Magistrato
Au(III) compounds have been also object of research interest [146]. Recently, [Au(III)(phen)Cl2]Cl (phen = 1,10-phenanthroline)], AuPhen, was identified as a selective and potent inhibitor of human aquaporin-3 (AQP3). This is an aquaglyceroporin family member allowing permeation of water and small uncharged solutes such as glycerol. Remarkably, AQP3 overexpression is linked to cancer development and obesity [153]. A computational workflow, composed of docking, FF-based MD, and QM/MM calculations, was applied to Auphen and other similar Au(III) complexes to predict their binding mode to AQP3’s channel. Interestingly, Au(III) binding to Cys40 induces thorough conformational changes of the aquaglyceroporin channel, ultimately leading to pore shrinkage and inhibition of substrate permeation [33].
Therapeutic effects of Bombax ceiba flower aqueous extracts against loperamide-induced constipation in mice
Published in Pharmaceutical Biology, 2023
Liuping Wang, Shiyuan Xie, Xuan Jiang, Caini Xu, Youqiong Wang, Jianfang Feng, Bin Yang
Constipation is a clinically common digestive disease in modern society (Chen et al. 2019; Lu et al. 2021), characterized by difficult excretion, low-frequency defecation, hard-dry stool and prolonged gastrointestinal emptying time (Li et al. 2020). Previous surveys showed that the prevalence of constipation ranged from approximately 2–30%, especially in elderly populations and children (Zhao et al. 2019; Gan et al. 2020). Long-term constipation may cause not only feelings of discomfort (Lu et al. 2021), but also gastrointestinal nerve dysfunction, intestinal flora disturbances (Wang et al. 2017), hepatic encephalopathy, cardiocerebrovascular disease (Payne and Grimm 2017), and even fatal pulmonary embolism (Yin et al. 2018) or colorectal cancer (Gan et al. 2020). The cause of constipation may have various factors, including a low-fibre diet, low physical activity, low water intake, medicine abuse (Hayeeawaema et al. 2020), lifestyle changes (Wang et al. 2017). Constipation is also one of the most common non-motor symptoms of Parkinson’s disease, and the most common gastrointestinal symptoms in alimentary tract tumour, inflammatory bowel disease, diabetes, metabolic and endocrine disorders, hyperparathyroidism, hypothyroidism and other neurological diseases (Gao et al. 2021). At present, the pathogenesis of constipation may include changes in gastrointestinal peptides hormones and aquaporins, colonic dysfunction, and abnormal interstitial cells of Cajal (ICC) (Liu et al. 2020). The gastrointestinal tract can produce a variety of gastrointestinal peptides hormones, including inhibitory transmitters represented by somatostatin (SS) and excitatory transmitters represented by motilin (MTL) (Liu et al. 2020), gastrin (Gas), substance P (SP), etc. (Han 2013; Gan et al. 2020). Aquaporin 3 (AQP3) is an important aquaporin located in the colon, which play an important role in the water transport effect (Ikarashi et al. 2016). In addition, some studies have shown that ICC is a pacemaker of the intestine (Han et al. 2010; Liu et al. 2020) and constipation is associated with loss and injury to ICC in the gastrointestinal tract (Huizinga and Chen 2014). The stem cell factor and its receptor tyrosine kinase (SCF/C-kit) signalling pathway could affect the phenotype of ICC and it may provide an important target for the therapy of constipation (Li et al. 2019).