scholarly journals Hormonal Regulation of Oligodendrogenesis I: Effects across the Lifespan

Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 283 ◽  
Author(s):  
Kimberly L. P. Long ◽  
Jocelyn M. Breton ◽  
Matthew K. Barraza ◽  
Olga S. Perloff ◽  
Daniela Kaufer
Keyword(s):  
Immune System ◽  
White Matter ◽  
Hormonal Regulation ◽  
Mechanisms Of Action ◽  
Adult Brain ◽  
Physiological Conditions ◽  
Changing Environments ◽  
Complex Interactions ◽  
Specific Receptors

The brain’s capacity to respond to changing environments via hormonal signaling is critical to fine-tuned function. An emerging body of literature highlights a role for myelin plasticity as a prominent type of experience-dependent plasticity in the adult brain. Myelin plasticity is driven by oligodendrocytes (OLs) and their precursor cells (OPCs). OPC differentiation regulates the trajectory of myelin production throughout development, and importantly, OPCs maintain the ability to proliferate and generate new OLs throughout adulthood. The process of oligodendrogenesis, the creation of new OLs, can be dramatically influenced during early development and in adulthood by internal and environmental conditions such as hormones. Here, we review the current literature describing hormonal regulation of oligodendrogenesis within physiological conditions, focusing on several classes of hormones: steroid, peptide, and thyroid hormones. We discuss hormonal regulation at each stage of oligodendrogenesis and describe mechanisms of action, where known. Overall, the majority of hormones enhance oligodendrogenesis, increasing OPC differentiation and inducing maturation and myelin production in OLs. The mechanisms underlying these processes vary for each hormone but may ultimately converge upon common signaling pathways, mediated by specific receptors expressed across the OL lineage. However, not all of the mechanisms have been fully elucidated, and here, we note the remaining gaps in the literature, including the complex interactions between hormonal systems and with the immune system. In the companion manuscript in this issue, we discuss the implications of hormonal regulation of oligodendrogenesis for neurological and psychiatric disorders characterized by white matter loss. Ultimately, a better understanding of the fundamental mechanisms of hormonal regulation of oligodendrogenesis across the entire lifespan, especially in vivo, will progress both basic and translational research.

scholarly journals Hormonal Regulation of Oligodendrogenesis I: Effects across the Lifespan

2021 ◽  
Author(s):  
Kimberly Long ◽  
Jocelyn Breton ◽  
Matthew Barraza ◽  
Olga Litvin ◽  
Daniela Kaufer
Keyword(s):  
Immune System ◽  
Hormonal Regulation ◽  
Mechanisms Of Action ◽  
Adult Brain ◽  
Physiological Conditions ◽  
Changing Environments ◽  
Complex Interactions ◽  
Specific Receptors ◽  
The Brain

The brain’s capacity to respond to changing environments via hormonal signaling is critical to fine-tuned function. An emerging body of literature highlights a role for myelin plasticity as a prominent type of experience-dependent plasticity in the adult brain. Myelin plasticity is driven by oligodendrocytes (OLs) and their precursor cells (OPCs). OPC differentiation regulates the trajectory of myelin production throughout development, and importantly, OPCs maintain the ability to proliferate and generate new OLs throughout adulthood. The process of oligodendrogenesis (OLgenesis), the creation of new OLs, can be dramatically influenced during early development and in adulthood by internal and environmental conditions such as hormones. Here, we review the current literature describing hormonal regulation of OLgenesis within physiological conditions, focusing on several classes of hormones: steroid, peptide, and thyroid hormones. We discuss hormonal regulation at each stage of OLgenesis and describe mechanisms of action, where known. Overall, the majority of hormones enhance OLgenesis, increasing OPC differentiation and inducing maturation and myelin production in OLs. The mechanisms underlying these processes vary for each hormone but may ultimately converge upon common signaling pathways, mediated by specific receptors expressed across the OL lineage. However, not all of the mechanisms have been fully elucidated, and here, we note the remaining gaps in the literature, including the complex interactions between hormonal systems and with the immune system. In the companion manuscript in this issue [1], we discuss the implications of hormonal regulation of OLgenesis for neurological and psychiatric disorders characterized by white matter loss. Ultimately, a better understanding of the fundamental mechanisms of hormonal regulation of OLgenesis across the entire lifespan, especially in vivo, will progress both basic and translational research.

Traditional Medicines, HIV, and Related Infections

2011 ◽  
Vol 23 (1) ◽  
pp. 159-164 ◽  
Author(s):  
M. Patel ◽  
P. Bessong ◽  
H. Liu
Keyword(s):  
Clinical Trials ◽  
Immune System ◽  
Ethical Issues ◽  
Mechanisms Of Action ◽  
Antiretroviral Drugs ◽  
In Vivo Studies ◽  
Traditional Medicines ◽  
Anti Hiv

Traditional medicines are an integral part of health care worldwide, even though their efficacy has not been scientifically proven. HIV-infected individuals may use them singularly or in combination with conventional medicines. Many in vitro studies have proven the anti-HIV, anti- Candida, and anti–herpes simplex virus potential of traditional plants and identified some of the mechanisms of action. Very few in vivo studies are available that involve a small number of participants and show controversial results. In addition, knowledge is limited of the role of traditional medicines in the enhancement of the immune system. The use of traditional medicines with antiretroviral drugs (ARVs) has created a problem because drug interactions compromise the efficacy of ARVs. Several currently popular plants have been studied in the laboratory for their interaction with ARVs, with disadvantageous results. Unfortunately, no clinical trials are available. The science of traditional medicines is relatively new and is at present being modernized worldwide. However, there are still ethical issues regarding traditional medicines that need to be addressed—for example, regulations regarding quality control and standardization of medicines, regulation and education of healers who deliver these medicines, and unregulated clinical trials. The workshop addressed the following questions about traditional medicine and their use in HIV infection: What are the mechanisms of action of anti-HIV traditional medicines? Should traditional medicines be used in conjunction with ARV? Do traditional medicines enhance the immune system? Should medicinal plants be used for the control of oral infections associated with HIV? What are the ethical issues surrounding the use of traditional medicines for the treatment of HIV and associated infections?

scholarly journals Vitamin C biochemistry: From scurvy to COVID-19 treatment

2020 ◽  
Vol 61 (2) ◽  
pp. 59-70
Author(s):  
Tamara Zakić ◽  
Marta Budnar ◽  
Anđelika Kalezić ◽  
Aleksandra Korać ◽  
Aleksandra Janković ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Immune System ◽  
Vitamin C ◽  
Mechanism Of Action ◽  
Mechanisms Of Action ◽  
System Function ◽  
Physiological Conditions ◽  
Immune System Function ◽  
Oxidation Reduction ◽  
New Challenges

The story of vitamin C (L-ascorbic acid) as an antioxidant and a cofactor in numerous biochemical reactions is a part of its long history and it is well known today. However, many questions of its mechanism of action and the benefits that it has on human health are still emerging. This applies not only to the recommended doses but also to the route of its administration. Besides, there are numerous questions about the therapeutic efficacy of vitamin C in various human (infectious) diseases, as well as its immune system function and antiviral potential. The fact that vitamin C can act as a reductant (antioxidant) and a prooxidant further emphasizes its oxidation-reduction (redox) potential in real physiological conditions. Today, the question of the intravenous administration of vitamin C effect in patients with SARS-CoV-2 requires special attention. This review aims to showcase known facts about vitamin C and its mechanisms of action to better understand the current new challenges related to vitamin C.

scholarly journals Bilirubin and its Oxidation Products Damage Brain White Matter

2014 ◽  
Vol 34 (11) ◽  
pp. 1837-1847 ◽  
Author(s):  
Katarina Lakovic ◽  
Jinglu Ai ◽  
Josephine D'Abbondanza ◽  
Asma Tariq ◽  
Mohammed Sabri ◽  
...  
Keyword(s):  
White Matter ◽  
Dimethyl Sulfoxide ◽  
Brain Slices ◽  
Structure And Function ◽  
Adult Brain ◽  
Oxidation Products ◽  
Unmyelinated Axons ◽  
And Function

Brain injury after intracerebral hemorrhage (ICH) occurs in cortex and white matter and may be mediated by blood breakdown products, including hemoglobin and heme. Effects of blood breakdown products, bilirubin and bilirubin oxidation products, have not been widely investigated in adult brain. Here, we first determined the effect of bilirubin and its oxidation products on the structure and function of white matter in vitro using brain slices. Subsequently, we determined whether these compounds have an effect on the structure and function of white matter in vivo. In all, 0.5 mmol/L bilirubin treatment significantly damaged both the function and the structure of myelinated axons but not the unmyelinated axons in brain slices. Toxicity of bilirubin in vitro was prevented by dimethyl sulfoxide. Bilirubin oxidation products (BOXes) may be responsible for the toxicity of bilirubin. In in vivo experiments, unmyelinated axons were found more susceptible to damage from bilirubin injection. These results suggest that unmyelinated axons may have a major role in white-matter damage in vivo. Since bilirubin and BOXes appear in a delayed manner after ICH, preventing their toxic effects may be worth investigating therapeutically. Dimethyl sulfoxide or its structurally related derivatives may have a potential therapeutic value at antagonizing axonal damage after hemorrhagic stroke.

scholarly journals Activation of a neural stem cell transcriptional program in parenchymal astrocytes

2020 ◽  
Author(s):  
Jens P. Magnusson ◽  
Margherita Zamboni ◽  
Giuseppe Santopolo ◽  
Jeff E. Mold ◽  
Mauricio Barrientos-Somarribas ◽  
...  
Keyword(s):  
Stem Cells ◽  
Neural Stem Cells ◽  
Subventricular Zone ◽  
Brain Regions ◽  
Adult Brain ◽  
Targeted Interventions ◽  
Physiological Conditions ◽  
Neuronal Lineage ◽  
Epidermal Growth

AbstractNeural stem cells, located in discrete niches in the adult brain, generate new neurons throughout life. These stem cells are specialized astrocytes, but astrocytes in other brain regions do not generate neurons under physiological conditions. After stroke, however, striatal astrocytes undergo neurogenesis in mice, triggered by decreased Notch signaling. We used single-cell RNA sequencing to characterize neurogenesis by Notch-depleted striatal astrocytes in vivo. Striatal astrocytes were located upstream of neural stem cells in the neuronal lineage. As astrocytes initiated neurogenesis, they became transcriptionally very similar to subventricular zone stem cells and progressed through a nearly identical neurogenic program. Surprisingly, in the non- neurogenic cortex, Notch-depleted astrocytes also initiated neurogenesis. Yet, the cortical astrocytes, and many striatal ones, stalled before entering transit- amplifying divisions. Infusion of epidermal growth factor enabled stalled striatal astrocytes to resume neurogenesis. We conclude that parenchymal astrocytes are latent neural stem cells and that targeted interventions can guide them through their neuronal differentiation.

scholarly journals Ref(2)P, the Drosophila melanogaster homologue of mammalian p62, is required for the formation of protein aggregates in adult brain

2008 ◽  
Vol 180 (6) ◽  
pp. 1065-1071 ◽  
Author(s):  
Ioannis P. Nezis ◽  
Anne Simonsen ◽  
Antonia P. Sagona ◽  
Kim Finley ◽  
Sébastien Gaumer ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Protein Aggregates ◽  
Adult Brain ◽  
Aggregate Formation ◽  
Ubiquitinated Protein ◽  
Physiological Conditions ◽  
Binding Domains ◽  
Ubiquitin Binding ◽  
Autophagic Degradation

p62 has been proposed to mark ubiquitinated protein bodies for autophagic degradation. We report that the Drosophila melanogaster p62 orthologue, Ref(2)P, is a regulator of protein aggregation in the adult brain. We demonstrate that Ref(2)P localizes to age-induced protein aggregates as well as to aggregates caused by reduced autophagic or proteasomal activity. A similar localization to protein aggregates is also observed in D. melanogaster models of human neurodegenerative diseases. Although atg8a autophagy mutant flies show accumulation of ubiquitin- and Ref(2)P-positive protein aggregates, this is abrogated in atg8a/ref(2)P double mutants. Both the multimerization and ubiquitin binding domains of Ref(2)P are required for aggregate formation in vivo. Our findings reveal a major role for Ref(2)P in the formation of ubiquitin-positive protein aggregates both under physiological conditions and when normal protein turnover is inhibited.

Mechanisms of action of antihyperglycemic mexicanolides isolated from Swietenia humillis: in vivo and in silico approaches

Planta Medica ◽  
2016 ◽  
Vol 81 (S 01) ◽  
pp. S1-S381 ◽  
Author(s):  
B Ovalle-Magallanes ◽  
A Madariaga-Mazón ◽  
A Navarrete ◽  
R Mata
Keyword(s):  
In Silico ◽  
Mechanisms Of Action

Supramolecular Enhancement of Aminoxyl ORCA Contrast Agents

2019 ◽  
Author(s):  
Hamilton Lee ◽  
Jenica Lumata ◽  
Michael A. Luzuriaga ◽  
Candace Benjamin ◽  
Olivia Brohlin ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Side Effects ◽  
Magnetic Resonance ◽  
Tobacco Mosaic Virus ◽  
Contrast Agents ◽  
Single Molecule ◽  
Organic Radical ◽  
Resonance Imaging ◽  
Physiological Conditions

<div><div><div><p>Many contrast agents for magnetic resonance imaging are based on gadolinium, however side effects limit their use in some patients. Organic radical contrast agents (ORCAs) are potential alternatives, but are reduced rapidly in physiological conditions and have low relaxivities as single molecule contrast agents. Herein, we use a supramolecular strategy where cucurbit[8]uril binds with nanomolar affinities to ORCAs and protects them against biological reductants to create a stable radical in vivo. We further over came the weak contrast by conjugating this complex on the surface of a self-assembled biomacromolecule derived from the tobacco mosaic virus.</p></div></div></div>

In-vivo anti-oxidant screening of Tectona grandis extract

2020 ◽  
Vol 9 (1) ◽  
pp. 1-4
Author(s):  
Tamilarasi G P ◽  
Sabarees G
Keyword(s):  
Biochemical Parameters ◽  
Tectona Grandis ◽  
The Body ◽  
Altered Expression ◽  
Physiological Conditions ◽  
Synthetic Drugs ◽  
Significant Difference ◽  
Anti Oxidant ◽  
Radical Generation

Oxidation is an essential reaction in the human body, which determines the expression of proteins in the body. This results in the altered expression like rapid growth resulting in cancers and other disorders. Many synthetic drugs are available in the market that is effective in limiting the free radical generation and the reaction of radicals with cells. Unfortunately, all those synthetic drugs were found to cause side effects and adverse effects in the body. But given the accuracy of the predictability of the results and administration, this research focuses on testing the anti-oxidant efficiency in rat models testing the biochemical parameters. Investigations have also been done on the anti-oxidant activity of Tectona, but every research was concentrated to prove the anti-oxidant activity only. extract had been tested for anti-oxidant activity by estimating various tissue parameters and it showed better activity. As predicted, there is a significant difference in the and results which can be explained are due to the physiological conditions that exist inside the body.

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