Subject:
All Disciplines Arts & Humanities Biology & Life Sciences Business & Economics Chemistry & Materials Science Computer Science & Mathematics Engineering Environmental & Earth Sciences Medicine & Pharmacology Physical Sciences Public Health & Healthcare Social Sciences
Sort:
Hottest Latest Alphabetical (A-Z) Alphabetical (Z-A)
Type:
All Topic Review Biography
Topic Review
Age-Dependent Decline of NAD+—Universal Truth or Confounded Consensus?
Nicotinamide adenine dinucleotide (NAD+) is an essential molecule involved in various metabolic reactions, acting as an electron donor in the electron transport chain and as a co-factor for NAD+-dependent enzymes. Despite systematic claims of overall decline in NAD+ levels with aging in multiple species, including humans, the evidence to support such claims is very limited and often restricted to a single tissue or cell type. The literature on the topic has been reviewed and it is found that there is a need for much larger, preferably longitudinal, studies to assess how NAD+ levels develop with aging.
  • 729
  • 11 Jan 2022
Topic Review
Age-Related Alterations at Neuromuscular Junction
With advancing aging, a decline in physical abilities occurs, leading to reduced mobility and loss of independence. Although many factors contribute to the physio-pathological effects of aging, an important event seems to be related to the compromised integrity of the neuromuscular system, which connects the brain and skeletal muscles via motoneurons and the neuromuscular junctions (NMJs). NMJs undergo severe functional, morphological, and molecular alterations during aging and ultimately degenerate. The effect of this decline is an inexorable decrease in skeletal muscle mass and strength, a condition generally known as sarcopenia. Moreover, several studies have highlighted how the age-related alteration of reactive oxygen species (ROS) homeostasis can contribute to changes in the neuromuscular junction morphology and stability, leading to the reduction in fiber number and innervation. Increasing evidence supports the involvement of epigenetic modifications in age-dependent alterations of the NMJ. In particular, DNA methylation, histone modifications, and miRNA-dependent gene expression represent the major epigenetic mechanisms that play a crucial role in NMJ remodeling. It is established that environmental and lifestyle factors, such as physical exercise and nutrition that are susceptible to change during aging, can modulate epigenetic phenomena and attenuate the age-related NMJs changes.
  • 771
  • 15 Jun 2021
Topic Review
Age-Related Alternative Splicing
Alternative splicing changes are closely linked to aging, though it remains unclear if they are drivers or effects. As organisms age, splicing patterns change, varying gene isoform levels and functions. These changes may contribute to aging alterations rather than just reflect declining RNA quality control. Three main splicing types—intron retention, cassette exons, and cryptic exons—play key roles in age-related complexity. These events modify protein domains and increase nonsense-mediated decay, shifting protein isoform levels and functions. This may potentially drive aging or serve as a biomarker. Fluctuations in splicing factor expression also occur with aging. Somatic mutations in splicing genes can also promote aging and age-related disease. 
  • 218
  • 29 Dec 2023
Topic Review
Age-Related Changes of Gene Expression
An individual’s gene expression profile changes throughout their life. This change in gene expression is shaped by differences in physiological needs and functions between the younger and older organism. Despite intensive studies, the aging process is not fully understood, and several genes involved in this process may remain to be identified. In this study authors compared the expression profiles of two-day-old female adult Drosophila flies with 45-day-old flies. They identified 1184 genes with pronounced differences in expression level between young and old age groups, including 232 genes with unknown functions. Authors characterized the subcellular localization of twelve of them and discovered that knockdown of some of them affects the lifespan of flies.
  • 379
  • 23 Dec 2021
Topic Review
Age-Related Hearing Loss
Age-related hearing impairment, also referred to as presbycusis, is the most common sensory impairment seen in the elderly. As our cochlea, the peripheral organ of hearing, ages, we tend to experience a decline in hearing and are at greater risk of cochlear sensory-neural cell degeneration and exacerbated age-related hearing impairments (e.g., gradual hearing loss, deterioration in speech comprehension, difficulty in the localization sound sources, and ringing sensations in the ears). Here, we outline recent research into major causal factors of age-related hearing loss including both extrinsic (e.g. noise and ototoxic medication), and intrinsic factors (e.g. genetic predisposition, epigenetic factors and aging).
  • 891
  • 23 Oct 2020
Topic Review
Age-Related Lysosomal Dysfunctions
Aging is a process associated with the detriment of normal physiological functions, which leads to the manifestation of diverse diseases such as cardiovascular and neurodegenerative diseases, joint degenerative diseases, and metabolic diseases such as diabetes, among others. Lysosomes are heterogeneous organelles enclosed by a lipid bilayer and filled with hydrolytic enzymes. The lysosomes are traditionally described as the subcellular structures where the degradation of other organelles and macromolecules takes place, a fundamental process for maintaining cellular proteostasis. There are several degradation processes in which the lysosomes are involved. If the substrate reaching the lysosomes comes from the extracellular environment, the degradation process is called endocytosis. If the material to be digested comes from the cell itself, the process is classified as autophagy. The lysosomes are also involved in plasma membrane repair through a mechanism called lysosomal exocytosis.  During aging, damage in cellular organelles disbalances the cellular homeostatic processes. Lysosomal dysfunction is emerging as an important factor that could regulate the production of inflammatory molecules, metabolic cellular state, or mitochondrial function. Thus, lysosomal alkalinization, amino acid storage, iron disturbances and lipofuscin accummulation are characteristic features of the lysosome during aging. 
  • 735
  • 30 Jul 2022
Topic Review
Ageing and Inflammation in Periodontium
Periodontitis is a ubiquitous chronic inflammatory disease characterized by the gradual destruction of the periodontal ligament and alveolar bone, leading to periodontal pocket formation and gingival recession. Ageing is a primary risk factor for the development of periodontitis, exacerbating alveolar bone loss and leading to tooth loss in the geriatric population.
  • 171
  • 24 Nov 2023
Topic Review
Ageritin from Pioppino Mushroom
Ageritin is a specific ribonuclease, extracted from the edible mushroom Cyclocybe aegerita (synonym Agrocybe aegerita), which cleaves a single phosphodiester bond located within the universally conserved alpha-sarcin loop (SRL) of 23–28S rRNAs.This toxin is the prototype of ribotoxin-like protein family present in edible mushroom and possesses antifungal/antiviral activities and selective cytotoxicity against tumor cells with potential use in biotechnological applications (as bio-insecticides or antitumor agents).
  • 748
  • 14 Apr 2021
Topic Review
Aggression in Dogs
Aggression as a behavior is not always desirable, often ends in abandonment and/or euthanasia. However, it is possible to prevent the occurrence of unwanted aggression in domestic dogs. Aggression is not a fully understood phenomenon. To aim to generalize the dogs’ behavior and understand their behavioral needs, ethograms have been developed. Communication of any kind, including aggression, is a natural part of a dog’s ethogram. An ethogram is a species-specific list of natural behavior. Dog ethograms include affiliate, agonistic, defensive, sedative, sexual, demonstrative, warning, stressful, playful, grooming, exploratory, related to hunting, or related to the reduction of stress.
  • 867
  • 11 Mar 2022
Topic Review
Aging and Bone Marrow
The aging of bone marrow (BM) remains a very imperative and alluring subject, with an ever-increasing interest among fellow scientists. A considerable amount of progress has been made in this field with the established ‘hallmarks of aging’ and continued efforts to investigate the age-related changes observed within the BM. Inflammaging is considered as a low-grade state of inflammation associated with aging, and whilst the possible mechanisms by which aging occurs are now largely understood, the processes leading to the underlying changes within aged BM remain elusive. The ability to identify these changes and detect such alterations at the genetic level are key to broadening the knowledgebase of aging BM. Next-generation sequencing (NGS) is an important molecular-level application presenting the ability to not only determine genomic base changes but provide transcriptional profiling (RNA-seq), as well as a high-throughput analysis of DNA–protein interactions (ChIP-seq). Utilising NGS to explore the genetic alterations occurring over the aging process within alterative cell types facilitates the comprehension of the molecular and cellular changes influencing the dynamics of aging BM.
  • 527
  • 15 Nov 2021
  • Page
  • of
  • 1814
Featured Entry Collections
>>

Featured Books

>>
Encyclopedia of Social Sciences
Encyclopedia of COVID-19
Encyclopedia of Fungi
Encyclopedia of Digital Society, Industry 5.0 and Smart City
Video Production Service
Feedback