Transgenic systems as a tool to probe essential components in physiological processes

Author(s):  
Ramon Serrano ◽  
A. Spena ◽  
E. Weiler ◽  
J. Morré
2020 ◽  
Vol 319 (5) ◽  
pp. H1069-H1077 ◽  
Author(s):  
Jingwei Jiang ◽  
Donald A. Morgan ◽  
Huxing Cui ◽  
Kamal Rahmouni

Agouti-related peptide (AgRP)- and proopiomelanocortin (POMC)-expressing neurons of the arcuate nucleus are essential components of the brain melanocortin system that controls various physiological processes. Here, we tested the metabolic and cardiovascular effects of direct activation of these two populations of neurons. Our findings show that, in addition to stimulation of food intake, chemogenetic mediated activation of hypothalamic arcuate nucleus AgRP, but not POMC, neurons reduce renal sympathetic traffic. Despite this, chronic activation of AgRP neurons increased blood pressure. However, chronic activation of POMC neurons led to a significant reduction in blood pressure. Our findings highlight the importance of arcuate nucleus AgRP and POMC neuronal activity in autonomic and cardiovascular regulation.


2016 ◽  
Vol 63 (3) ◽  
Author(s):  
Ibeth Guevara-Lora ◽  
Anna Niewiarowska-Sendo ◽  
Agnieszka Polit ◽  
Andrzej Kozik

The G protein-coupled receptors (GPCRs), one of the largest protein families, are essential components of the most commonly used signal-transduction systems in cells. These receptors, often using common pathways, may cooperate in the regulation of signal transmission to the cell nucleus. Recent scientific interests increasingly focus on the cooperation between these receptors, particularly in a context of their oligomerization, e.g. the formation of dimers that are able to change characteristic signaling of each receptor. Numerous studies on kinin and dopamine receptors which belong to this family of receptors have shown new facts demonstrating their direct interactions with other GPCRs. In this review, current knowledge on signaling pathways and oligomerization of these receptors has been summarized. Owing to the fact that kinin and dopamine receptors are widely expressed in cell membranes where they act as mediators of numerous common physiological processes, the information presented here sheds new light on a putative crosstalk of these receptors and provides more comprehensive understanding of possible direct interactions that may change their functions. The determination of such interactions may be useful for the development of new targeted therapeutic strategies against many disorders in which kinin and dopamine receptors are involved.


2020 ◽  
Vol 33 (12) ◽  
pp. 1885-1895
Author(s):  
Santi Devi Upadhaya ◽  
In Ho Kim

Vitamins and minerals categorized as micronutrients are the essential components of animal feed for maintaining health and improving immunity. Micronutrients are important bioactive molecules and cofactors of enzymes as well. Besides being cofactors for enzymes, some vitamins such as the fat-soluble vitamins, vitamin A and D have been shown to exhibit hormone-like functions. Although they are required in small amount, they play an influential role in the proper functioning of a number of enzymes which are involved in many metabolic, biochemical and physiological processes that contribute to growth, production and health. Micronutrients can potentially have a positive impact on bone health, preventing bone loss and fractures, decreasing bone resorption and increasing bone formation. Thus, micronutrients must be provided to livestock in optimal concentrations and according to requirements that change during the rapid growth and development of the animal and the production cycle. The supply of nutrients to the animal body not only depends on the amount of the nutrient in a food, but also on its bioavailability. The bioavailability of these micronutrients is affected by several factors. Therefore, several technologies such as nanoparticle, encapsulation, and chelation have been developed to improve the bioavailability of micronutrients associated with bone health. The intention of this review is to provide an updated overview of the importance of micronutrients on bone health and methods applied to improve their bioavailability.


2021 ◽  
Vol 7 (10) ◽  
pp. eabd6480
Author(s):  
M. Suzuki ◽  
T. Sujino ◽  
S. Chiba ◽  
Y. Harada ◽  
M. Goto ◽  
...  

Organisms use l-amino acids (l-aa) for most physiological processes. Unlike other organisms, bacteria chiral-convert l-aa to d-configurations as essential components of their cell walls and as signaling molecules in their ecosystems. Mammals recognize microbe-associated molecules to initiate immune responses, but roles of bacterial d-amino acids (d-aa) in mammalian immune systems remain largely unknown. Here, we report that amino acid chirality balanced by bacteria-mammal cross-talk modulates intestinal B cell fate and immunoglobulin A (IgA) production. Bacterial d-aa stimulate M1 macrophages and promote survival of intestinal naïve B cells. Mammalian intestinal d-aa catabolism limits the number of B cells and restricts growth of symbiotic bacteria that activate T cell–dependent IgA class switching of the B cells. Loss of d-aa catabolism results in excessive IgA production and dysbiosis with altered IgA coating on bacteria. Thus, chiral conversion of amino acids is linked to bacterial recognition by mammals to control symbiosis with bacteria.


Author(s):  
James Cronshaw ◽  
Jamison E. Gilder

Adenosine triphosphatase (ATPase) activity has been shown to be associated with numerous physiological processes in both plants and animal cells. Biochemical studies have shown that in higher plants ATPase activity is high in cell wall preparations and is associated with the plasma membrane, nuclei, mitochondria, chloroplasts and lysosomes. However, there have been only a few ATPase localization studies of higher plants at the electron microscope level. Poux (1967) demonstrated ATPase activity associated with most cellular organelles in the protoderm cells of Cucumis roots. Hall (1971) has demonstrated ATPase activity in root tip cells of Zea mays. There was high surface activity largely associated with the plasma membrane and plasmodesmata. ATPase activity was also demonstrated in mitochondria, dictyosomes, endoplasmic reticulum and plastids.


Author(s):  
A. E. Hotchkiss ◽  
A. T. Hotchkiss ◽  
R. P. Apkarian

Multicellular green algae may be an ancestral form of the vascular plants. These algae exhibit cell wall structure, chlorophyll pigmentation, and physiological processes similar to those of higher plants. The presence of a vascular system which provides water, minerals, and nutrients to remote tissues in higher plants was believed unnecessary for the algae. Among the green algae, the Chaetophorales are complex highly branched forms that might require some means of nutrient transport. The Chaetophorales do possess apical meristematic groups of cells that have growth orientations suggestive of stem and root positions. Branches of Chaetophora incressata were examined by the scanning electron microscope (SEM) for ultrastructural evidence of pro-vascular transport.


2009 ◽  
Vol 14 (2) ◽  
pp. 109-119 ◽  
Author(s):  
Ulrich W. Ebner-Priemer ◽  
Timothy J. Trull

Convergent experimental data, autobiographical studies, and investigations on daily life have all demonstrated that gathering information retrospectively is a highly dubious methodology. Retrospection is subject to multiple systematic distortions (i.e., affective valence effect, mood congruent memory effect, duration neglect; peak end rule) as it is based on (often biased) storage and recollection of memories of the original experience or the behavior that are of interest. The method of choice to circumvent these biases is the use of electronic diaries to collect self-reported symptoms, behaviors, or physiological processes in real time. Different terms have been used for this kind of methodology: ambulatory assessment, ecological momentary assessment, experience sampling method, and real-time data capture. Even though the terms differ, they have in common the use of computer-assisted methodology to assess self-reported symptoms, behaviors, or physiological processes, while the participant undergoes normal daily activities. In this review we discuss the main features and advantages of ambulatory assessment regarding clinical psychology and psychiatry: (a) the use of realtime assessment to circumvent biased recollection, (b) assessment in real life to enhance generalizability, (c) repeated assessment to investigate within person processes, (d) multimodal assessment, including psychological, physiological and behavioral data, (e) the opportunity to assess and investigate context-specific relationships, and (f) the possibility of giving feedback in real time. Using prototypic examples from the literature of clinical psychology and psychiatry, we demonstrate that ambulatory assessment can answer specific research questions better than laboratory or questionnaire studies.


2007 ◽  
Author(s):  
N. Kalezic ◽  
U. Aasa ◽  
M. Barnekow-Bergkvist ◽  
E. Lyskov

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