Topic Review
Cataracts
A cataract is an ophthalmic disorder characterized by the opacification of the lens and occurs commonly in older people. Age-related cataract is a significant cause of blindness affecting the quality of life worldwide. An imbalance between oxidative stress and antioxidant potential of ocular tissue is considered responsible for structural modifications of crystallins, the protein constituents of the lens, which eventually leads to cataracts. Lutein and zeaxanthin are two major carotenoids which are concentrated in the human lens. Many preclinical and clinical studies provide compelling evidence for a protective role of dietary carotenoids in age-related cataracts.
  • 980
  • 28 Sep 2021
Topic Review
Vitamin D, Oxidative-Stress and Aging
Recent advances in vitamin D research indicate that this vitamin, a secosteroid hormone, has beneficial effects on several body systems other than the musculoskeletal system. Both 25 dihydroxy vitamin D [25(OH)2D] and its active hormonal form, 1,25-dihydroxyvitamin D [1,25(OH)2D] are essential for human physiological functions, including damping down inflammation and the excessive intracellular oxidative stresses. Vitamin D is one of the key controllers of systemic inflammation, oxidative stress and mitochondrial respiratory function, and thus, the aging process in humans. In turn, molecular and cellular actions form 1,25(OH)2D slow down oxidative stress, cell and tissue damage, and the aging process. On the other hand, hypovitaminosis D impairs mitochondrial functions, and enhances oxidative stress and systemic inflammation. The interaction of 1,25(OH)2D with its intracellular receptors modulates vitamin D–dependent gene transcription and activation of vitamin D-responsive elements, which triggers multiple second messenger systems. Thus, it is not surprising that hypovitaminosis D increases the incidence and severity of several age-related common diseases, such as metabolic disorders that are linked to oxidative stress. These include obesity, insulin resistance, type 2 diabetes, hypertension, pregnancy complications, memory disorders, osteoporosis, autoimmune diseases, certain cancers, and systemic inflammatory diseases. Vitamin D adequacy leads to less oxidative stress and improves mitochondrial and endocrine functions, reducing the risks of disorders, such as autoimmunity, infections, metabolic derangements, and impairment of DNA repair; all of this aids a healthy, graceful aging process. Vitamin D is also a potent anti-oxidant that facilitates balanced mitochondrial activities, preventing oxidative stress-related protein oxidation, lipid peroxidation, and DNA damage. New understandings of vitamin D-related advances in metabolomics, transcriptomics, epigenetics, in relation to its ability to control oxidative stress in conjunction with micronutrients, vitamins, and antioxidants, following normalization of serum 25(OH)D and tissue 1,25(OH)2D concentrations, likely to promise cost-effective better clinical outcomes in humans. 
  • 892
  • 29 Oct 2020
Topic Review
Xanthine Oxidoreductase Activities
Xanthine oxidoreductase (XOR) is the enzyme that catalyzes the oxidation of hypoxanthine to xanthine and xanthine to uric acid. XOR is widely distributed throughout living organisms and is highly conserved in prokaryotic, plant, and animal species. XOR activity is very versatile, generating both pro-oxidant (primarily within the cell) and anti-oxidant (primarily in plasma) products.
  • 806
  • 21 Sep 2020
Topic Review
EMT Program in Breast cancer
Notch signaling is a primitive signaling pathway having various roles in the normal origin and development of each multicellular organisms. Therefore, any aberration in the pathway will inevitably lead to deadly outcomes such as cancer. It has now been more than two decades since Notch was acknowledged as an oncogene in mouse mammary tumor virus-infected mice. Since that discovery, activated Notch signaling and consequent up-regulation of tumor-promoting Notch target genes have been observed in human breast cancer. Moreover, consistent over-expression of Notch ligands and receptors has been shown to correlate with poor prognosis in human breast cancer. Notch regulates a number of key processes during breast carcinogenesis, of which, one key phenomenon is epithelial–mesenchymal transition (EMT). EMT is a key process for large-scale cell movement during morphogenesis at the time of embryonic development. Cancer cells aided by transcription factors usurp this developmental program to execute the multi-step process of tumorigenesis and metastasis. In this review, we recapitulate recent progress in breast cancer research that has provided new perceptions into the molecular mechanisms behind Notch-mediated EMT regulation during breast tumorigenesis.
  • 749
  • 29 Oct 2020
Topic Review
Melanin regulation peptides
Certain analogs of α-melanocyte stimulating hormone (MSH) and peptides with the sequences derived from the hormone were shown to promote or suppress melanin synthesis in cells and in vivo models. Various amino acids, peptides, their analogs, and their hybrid compounds with other chemical moieties were shown to inhibit tyrosinase (TYR) catalytic activity or downregulate TYR gene expression. Certain peptides were shown to inhibit melanosome biogenesis or induce autophagy, leading to decreased pigmentation. In vivo and clinical evidence are available for some compounds, including [Nle4-D-Phe7]-α-MSH, glutathione disulfide, and glycinamide hydrochloride.
  • 689
  • 28 Sep 2021
Topic Review
Updated Understanding of Cancer
       Cancer is a tumorigenesis process that forms a mass of cells that we call a tumor. During tumorigenesis, the cells that compose the tumor can be benign or malignant. When the cells in the tumor are normal but old, the tumor is termed benign. When the cells in the tumor are abnormal and can grow uncontrollably, the tumor is malignant. Sometimes a benign tumor can transform into a malign one if the normal old cells begin to develop abnormalities, such as DNA mutations, and grow rapidly. - by Cristian Muresanu
  • 578
  • 30 Oct 2020
Topic Review
T2DM and the Gut Microbiota
Type 2 Diabetes Mellitus (T2DM) affects over 9% of the United States population alone, constitutes a cause for ensuing cardiovascular disease, and is typically closely linked to obesity status. While obesity has long been perceived to stem from a sedentary lifestyle and high fat intake there is increasing evidence supporting the idea that this is a more complex issue than initially thought. The human gut microbiome has been a recent point of investigation due to the idea that it may be closely linked to T2DM. The aforementioned high fat diets can impact the gut microbiome in a significant way, altering the demography of the gut’s microflora, hence shifting the gut into a state of dysbiosis. Dysbiosis is a state that favors the initiation of a cascade inducing metabolic deregulation, increasing inflammation and insulin resistance systemically. Below the relationship of the microbiome to T2DM is briefly discussed.
  • 532
  • 29 Oct 2020
Topic Review
Exercise influence on calcium-phosphorous metabolism
Exercise perturbs homeostasis, alters the levels of circulating mediators and hormones, and increases the demand by skeletal muscles and other vital organs for energy substrates. Exercise also affects bone and mineral metabolism, particularly calcium and phosphate, both of which are essential for muscle contraction, neuromuscular signaling, biosynthesis of adenosine triphosphate (ATP), and other energy substrates. Parathyroid hormone (PTH) is involved in the regulation of calcium and phosphate homeostasis. Understanding the e ects of exercise on PTH secretion is fundamental for appreciating how the body adapts to exercise.
  • 528
  • 26 Aug 2020
Topic Review
B-Cell Lymphoma-Extra-Large
B-Cell Lymphoma-extra-large (BCL-xL) is involved in longevity and successful aging,which indicates a role for BCL-xL in cell survival pathway regulation. Beyond its well described role as an inhibitor of apoptosis by preventing cytochrome c release, BCL-xL has also been related, indirectly, to autophagy and senescence pathways. Although in these latter cases, BCL-xL has dual roles, either activating or inhibiting, depending on the cell type and the specific conditions. Taken together, all these findings suggest a precise mechanism of action for BCL-xL, able to regulate the crosstalk between apoptosis, autophagy, and senescence, thus promoting cell survival or cell death. All three pathways can be both beneficial or detrimental depending on the circumstances. Thus, targeting BCL-xL would in turn be a “double-edge sword” and therefore, additional studies are needed to better comprehend this dual and apparently contradictory role of BCL-XL in longevity.
  • 440
  • 31 Jul 2020
Topic Review
Calcium Phosphate Nanocluster Complexes
Calcium phosphate nanocluster complexes comprise a core of amorphous calcium phosphate and a sequestering shell of intrinsically disordered phosphopeptides or phosphoproteins. Solutions containing the nanocluster complexes can be thermodynamically stable or metastable due to a tendency to form a precipitate enriched in calcium phosphate. Theoretical and biophysical studies with native and recombinant phosphopeptides have shown how the radius of the core and the stability of the solution depend on the concentration of the sequestering peptide, its affinity for the calcium phosphate and its concentration in relation to the concentration of the calcium phosphate. The thickness of the sequestering shell depends on the conformation of the peptide on the core surface. A sequestering peptide is a flexible sequence including one or more short linear motifs, each of which usually contains several phosphorylated and other acidic residues.  These are the main binding sites to the core so that a peptide with several binding motifs can forms loops and trains on the core surface. Calcium phosphate nanocluster complexes were first identified as substructures of casein micelles in milk and have been prepared as individual particles from peptides derived from caseins and osteopontin. Stable biofluids containing nanocluster complexes cannot cause soft tissues to become mineralized whereas stable or metastable biofluids containing nanocluster complexes can help to mineralize hard tissues.
  • 432
  • 09 Nov 2020
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