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Topic Review
Nutraceuticals for Diabetic Retinopathy Treatment
Diabetic retinopathy (DR) is one of the most common complications of diabetes mellitus and is characterized by degeneration of retinal neurons and neoangiogenesis, causing a severe threat to vision. Nowadays, the principal treatment options for DR are laser photocoagulation, vitreoretinal surgery, or intravitreal injection of drugs targeting vascular endothelial growth factor. Treatment with nutraceuticals (foods providing medical or health benefits) at early stages of DR may represent a reasonable alternative to act upstream of the disease, preventing its progression.
  • 909
  • 12 Oct 2021
Topic Review
Vitamin C against COVID-19
Vitamin C is a nutrient required as a cofactor for multiple enzymatic reactions, such us norepinephrine biosynthesis, collagen hydroxylation, or amidation of peptide hormones. Additionally, it exerts a wide range of properties that could come in handy for the prevention and treatment of infections, including antioxidant, immunomodulating, as well as antiviral and antithrombotic functions.
  • 909
  • 10 Jan 2022
Topic Review
Alternative Organism Models for Retina Neuroregeneration
Unlike in vitro cell cultures that cannot mimic tissue homeostasis and physiology, 3D retinal organoids are relatively cheap models and have an undeniable complexity rate. However, they are challenging to isolate and maintain long enough to investigate complex processes such as inflammation and neovascularization. These disadvantages are exacerbated considering the retina, which is mainly due to the global complexity of this tissue. Several classic diagnostic techniques could be applied to retinal organ cultures, such as optical coherence tomography, which explores the morphological aspect of the retinal architecture, electroretinograms that record the electrical response of retinal cells, and microelectrode array recording, which stimulates and records the electrical activity of RGC. Several mammalian retinal organ cultures as alternative models are currently available and well established, including those derived from mice, rats, rabbits, cats, dogs, non-human primates, bovines, and pigs. They are excellent samples for the preliminary phase before the in vivo step and for therapy tests, although organ cultures for the study of complex retinal neurodegenerative pathologies such as diabetic retinopathy (DR), retinitis pigmentosa (RP), age-related macular degeneration, and glaucoma are not entirely reproducing the human condition. Although all the events occurring during the various steps of retinal neurodegenerative diseases, including the clinical progression, are not fully mimicked by a single animal, preclinical in vivo models provide important information on the molecular and cellular mechanisms at the basis of the neuronal impairment. Thus, multiple organisms, including non-mammalian ones, are crucial for validating the mechanisms involved in retinal pathologies and developing new therapeutic options.
  • 904
  • 28 Sep 2022
Topic Review
Haptoglobin
Haptoglobin (Hp) is an acute phase protein which supports the immune response and protects tissues from free radicals. Its concentration correlates with disease activity in spondyloarthropathies (SpAs).
  • 903
  • 27 Apr 2021
Topic Review
Pathophysiological Response to CnTX Voltage-Gated Channel Modulation
Voltage-gated ion channels are plasma membrane proteins that generate electrical signals following a change in the membrane voltage.
  • 903
  • 14 Jun 2022
Topic Review
Growth and Nutritional Quality of Lemnaceae
This entry focuses on recently characterized traits of the aquatic floating plant Lemna with an emphasis on its capacity to combine rapid growth with the accumulation of high levels of the essential human micronutrient zeaxanthin, due to an unusual pigment composition not seen in other fast-growing plants. In addition, Lemna’s response to elevated atmospheric carbon dioxide was evaluated in the context of the source–sink balance between plant sugar production and consumption. These and other traits of Lemnaceae are compared with those of other floating aquatic plants as well as terrestrial plants adapted to different environments. It was concluded that the unique features of aquatic plants reflect adaptations to the freshwater environment including rapid growth, high productivity, and exceptionally strong accumulation of high-quality vegetative storage protein and essential human antioxidant micronutrients. It was further concluded that the insensitivity of growth rate to environmental conditions and plant source–sink imbalance may allow duckweeds to take advantage of elevated atmospheric carbon dioxide levels via particularly strong stimulation of biomass production and either no (under favorable nutrient supply), or only minor (under limiting nutrient supply), declines in the growth of new tissue.
  • 899
  • 24 Jan 2022
Topic Review
Dopamine Levels and Metabolism in the Heart
Dopamine has effects on the mammalian heart. These effects can include an increase in the force of contraction, and an elevation of the beating rate and the constriction of coronary arteries. Depending on the species studied, positive inotropic effects were strong, very modest, or absent, or even negative inotropic effects occurred.
  • 896
  • 06 Sep 2023
Topic Review
STIM1 for Intracellular Calcium Handling
Stromal interacting molecule 1 (STIM1), a single transmembrane-spanning domain protein mainly residing in the endoplasmic reticulum (ER), is the unique ER Ca2+sensor deputed to ER Ca2+refilling. STIM1 was identified in 2005 by RNA interference-based screening of proteins with known signaling motifs. Molecularly, STIM1, residing into the organelle, senses luminal Ca2+ concentration by its N-terminus with a low affinity with an apparent dissociation constant (Kd) of ~0.2–0.6 mM and interferes with several plasma membrane ionic proteins. In this way, STIM1 coordinates the  complex Ca2+ entry mechanism called store-operated calcium entry (SOCE) deputed to ER Ca2+ recharge.
  • 888
  • 03 Mar 2022
Topic Review
Decreased Trabecular Bone Mass in Col22a1-Deficient Mice
The bone matrix is constantly remodeled by the coordinated activities of bone-forming osteoblasts and bone-resorbing osteoclasts. Whereas type I collagen is the most abundant bone matrix protein, there are several other proteins present, some of them specifically produced by osteoblasts. In a genome-wide expression screening for osteoblast differentiation markers we have previously identified two collagen-encoding genes with unknown function in bone remodeling. Here we show that one of them, Col22a1, is predominantly expressed in bone, cultured osteoblasts, but not in osteoclasts. Based on this specific expression pattern we generated a Col22a1-deficient mouse model, which was analyzed for skeletal defects by µCT, undecalcified histology and bone-specific histomorphometry. We observed that Col22a1-deficient mice display trabecular osteopenia, accompanied by significantly increased osteoclast numbers per bone surface. In contrast, cortical bone parameters, osteoblastogenesis or bone formation were unaffected by the absence of Col22a1. Likewise, primary osteoblasts from Col22a1-deficient mice did not display a cell-autonomous defect, and they did not show altered expression of Rankl or Opg, two key regulators of osteoclastogenesis. Taken together, we provide the first evidence for a physiological function of Col22a1 in bone remodeling, although the molecular mechanisms explaining the indirect influence of Col22a1 deficiency on osteoclasts remain to be identified. 
  • 883
  • 11 Nov 2021
Topic Review
Cholinergic Regulation of Hippocampal Theta Rhythm
Cholinergic regulation of hippocampal theta rhythm has been proposed as one of the central mechanisms underlying hippocampal functions including spatial memory encoding. However, cholinergic transmission has been traditionally associated with atropine-sensitive type II hippocampal theta oscillations that occur during alert immobility or in urethane-anesthetized animals. The role of cholinergic regulation of type I theta oscillations in behaving animals is much less clear. Recent studies strongly suggest that both cholinergic muscarinic and nicotinic receptors do actively regulate type I hippocampal theta oscillations and thus provide the cholinergic mechanism for theta-associated hippocampal learning. Septal cholinergic activation can regulate hippocampal circuit and theta expression either through direct septohippocampal cholinergic projections, or through septal glutamatergic and GABAergic neurons, that can precisely entrain hippocampal theta rhythmicity. 
  • 881
  • 06 Apr 2022
Topic Review
The Molecular Basis for Zinc Bioavailability
As an essential micronutrient with a nearly ubiquitous presence in nature, zinc is needed for all known aspects of life. Based on the quantification of putative zinc protein binding domains, it is estimated that one-tenth of all human proteins require zinc as a structural element or for an enzyme active site. The structural, catalytic, and regulatory roles of zinc provide the foundation for a broad array of basic cellular functions. Consequently, zinc deficiency affects numerous critical functions, including metabolic, immune, and neurological processes. With zinc nutriture underlying a public health burden of communicable and non-communicable diseases, human zinc deficiency is estimated to be the most prevalent nutrient deficiency worldwide. The etiology of human zinc deficiency has historically been attributed to diets with low zinc bioavailability, e.g., the proportion of dietary zinc available for zinc-dependent functions, with primary attention to diets low in zinc and high in phytic acid.
  • 881
  • 10 Apr 2023
Topic Review
Glucocorticoid/Adiponectin Axis
Glucocorticoids (GCs), a class of corticosteroids produced by the adrenal cortex in response to stress, exert obesity-promoting effects. 
  • 878
  • 11 Nov 2021
Topic Review
Aging and Nicotinamide Adenine Dinucleotide Deficiency
Under normal physiological conditions, nicotinamide adenine dinucleotide (NAD+) consumption is matched by its synthesis primarily via the salvage pathway catalyzed by nicotinamide phosphoribosyltransferase (NAMPT). However, aging and muscular contraction enhance NAD+ utilization, whereas NAD+ replenishment is limited by cellular sources of NAD+ precursors and/or enzyme expression.
  • 875
  • 18 Apr 2022
Topic Review
Ion Channels in GBM Cell Migration and Death
Ca2+-activated K+ channels of large- and intermediate-conductance (BK and IK, respectively) and the volume-regulated anion channel (VRAC), are the main K+ and Cl- channels highly-expressed in glioblastoma (GBM) cells, where they play an essential role in the control of cell volume and, in turn, migration, invasion, and apoptotic cell death, the three main features underlying GBM malignancy and lethality.
  • 875
  • 14 Dec 2023
Topic Review
Beta-Amyloid Instigates Dysfunction of Mitochondria in Cardiac Cells
Alzheimer’s disease (AD) includes the formation of extracellular deposits comprising aggregated β-amyloid (Aβ) fibers associated with oxidative stress, inflammation, mitochondrial abnormalities, and neuronal loss. There is an associative link between AD and cardiac diseases; however, the mechanisms underlying the potential role of AD, particularly Aβ in cardiac cells, remain unknown. Here, we investigated the role of mitochondria in mediating the effects of Aβ1-40 and Aβ1-42 in cultured cardiomyocytes and primary coronary endothelial cells. Our results demonstrated that Aβ1-40 and Aβ1-42 are differently accumulated in cardiomyocytes and coronary endothelial cells. Aβ1-42 had more adverse effects than Aβ1-40 on cell viability and mitochondrial function in both types of cells. Mitochondrial and cellular ROS were significantly increased, whereas mitochondrial membrane potential and calcium retention capacity decreased in both types of cells in response to Aβ1-42. Mitochondrial dysfunction induced by Aβ was associated with apoptosis of the cells. The effects of Aβ1-42 on mitochondria and cell death were more evident in coronary endothelial cells. In addition, Aβ1-40 and Aβ1-42 significantly increased Ca2+ -induced swelling in mitochondria isolated from the intact rat hearts. In conclusion, this study demonstrates the toxic effects of Aβ on cell survival and mitochondria function in cardiac cells. 
  • 870
  • 09 Feb 2022
Topic Review
ClC-1 Chloride Channel Structure and Myotonia-Causing Mutations Update
Myotonia congenita is a hereditary muscle disease mainly characterized by muscle hyperexcitability, which leads to a sustained burst of discharges that correlates with the magnitude and duration of involuntary aftercontractions, muscle stiffness, and hypertrophy. Mutations in the chloride voltage-gated channel 1 (CLCN1) gene that encodes the skeletal muscle chloride channel (ClC-1) are responsible for this disease, which is commonly known as myotonic chloride channelopathy. The structure of the channel has been updated and the biophysical properties of the mutated channel have been explored and analyzed, providing important clues to the general function/dysfunction of the wild-type and mutated channels.
  • 866
  • 02 Nov 2023
Topic Review
Sugar Metabolism and Its Effect on Adipose Tissue
Glucose, fructose, and galactose are widely used in the food industry as sweeteners and food additives. The over-consumption of these carbohydrates has been identified as a possible trigger of non-communicable diseases. These include insulin resistance, obesity, and type 2 diabetes. These sugars induce an energy overload with consequent adipose tissue (AT) expansion, contributing to the development of obesity and inflammation.
  • 863
  • 09 Feb 2023
Topic Review
Phenotypic Plasticity—Animals Adjusting to Environmental Conditions
Hyperplasia and hypertrophy or their counterparts, hypoplasia and hypotrophy, are elements of adjusting organ size and function in animals according to needs under altered environmental conditions. As such processes are costly in terms of energy and biomaterials, it is assumed that they are beneficial for the survival of the individual. The ability of animals to perform such adjustments and their limitations in scope are considered to be adaptive genetic traits which enable individual animals to survive regularly occurring changes in environmental conditions in their habitats as long as such changes stay within critical limits. The restructuring of mono-functional glands in ducklings which serve the animals to get rid of excess amounts of ingested salt from the body is presented as an example of complex plastic changes in organ structure. Phenotypic adjustments in these salt glands encompass processes which are reversible when environmental conditions switch back to the original state (‘phenotypic elasticity’) as well as irreversible ones (‘phenotypic plasticity’ in the narrow sense). As more information on genomes or transcriptomes of non-model animal species becomes available these days, researchers will better understand the biological significance of such phenotypic adjustments in animals in their natural environments and the underlying molecular mechanisms.
  • 862
  • 26 Jun 2023
Topic Review
Efficient Mucosal Repair Limits Morbidity from Colic
Colic is a leading cause of death in horses, with the most fatal form being strangulating obstruction which directly damages the intestinal barrier. Following surgical intervention, it is imperative that the intestinal barrier rapidly repairs to prevent translocation of gut bacteria and their products and ensure survival of the patient. Age-related disparities in survival have been noted in many species, including horses, humans, and pigs, with younger patients suffering poorer clinical outcomes. Maintenance and repair of the intestinal barrier is regulated by a complex mucosal microenvironment, of which the ENS, and particularly a developing network of subepithelial enteric glial cells, may be of particular importance in neonates with colic. Postnatal development of an immature enteric glial cell network is thought to be driven by the microbial colonization of the gut and therefore modulated by diet-influenced changes in bacterial populations early in life.
  • 860
  • 13 Dec 2021
Topic Review
The Gut Microbiota Function
The microbiota is known as the set of microorganisms residing in each ecosystem, with a symbiotic relationship and with adaptive properties and rapid renewal, forming a large metabolic unit. The intestinal microbiota is a set of microorganisms made up of approximately 100,000 million bacteria that live in people intestine. The microbiota is responsible, among other functions, for maintaining the well-being of the intestinal mucosa, helping digest food and converting harmful elements into less toxic substances.
  • 852
  • 17 Oct 2022
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