scholarly journals Satellite Cells Exhibit Decreased Numbers and Impaired Functions on Single Myofibers Isolated from Vitamin B6-Deficient Mice

Nutrients ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 4531
Author(s):  
Takumi Komaru ◽  
Noriyuki Yanaka ◽  
Thanutchaporn Kumrungsee

Emerging research in human studies suggests an association among vitamin B6, sarcopenia, and muscle strength. However, very little is known regarding its potential role at the cellular level, especially in muscle satellite cells. Therefore, to determine whether vitamin B6 affects the satellite cells, we isolated single myofibers from muscles of vitamin B6-deficient and vitamin B6-supplemented mice. Subsequently, we subjected them to single myofiber culture and observed the number and function of the satellite cells, which remained in their niche on the myofibers. Prior to culture, the vitamin B6-deficient myofibers exhibited a significantly lower number of quiescent satellite cells, as compared to that in the vitamin B6-supplemented myofibers, thereby suggesting that vitamin B6 deficiency induces a decline in the quiescent satellite cell pool in mouse muscles. After 48 and 72 h of culture, the number of proliferating satellite cells per cluster was similar between the vitamin B6-deficient and -supplemented myofibers, but their numbers decreased significantly after culturing the myofibers in vitamin B6-free medium. After 72 h of culture, the number of self-renewing satellite cells per cluster was significantly lower in the vitamin B6-deficient myofibers, and the vitamin B6-free medium further decreased this number. In conclusion, vitamin B6 deficiency appears to reduce the number of quiescent satellite cells and suppress the proliferation and self-renewal of satellite cells during myogenesis.

Blood ◽  
1998 ◽  
Vol 91 (8) ◽  
pp. 2745-2752 ◽  
Author(s):  
Timothy Gainsford ◽  
Andrew W. Roberts ◽  
Shinya Kimura ◽  
Donald Metcalf ◽  
Glenn Dranoff ◽  
...  

Mice lacking thrombopoietin (TPO), or its receptor c-Mpl, display defective megakaryocyte and platelet development and deficiencies in progenitor cells of multiple hematopoietic lineages. The contribution of alternative cytokines to thrombopoiesis in the absence of TPO signalling was examined in mpl−/− mice. Analysis of serum and organ-conditioned media showed no evidence of a compensatory overproduction of megakaryocytopoietic cytokines. However, consistent with a potential role in vivo, when injected intompl−/− mice, interleukin-6 (IL-6) and leukemia inhibitory factor (LIF) retained the capacity to elevate megakaryocytes and their progenitors in hematopoietic tissues and increase circulating platelet numbers. However, double mutant mice bred to carry genetic defects both in c-Mpl and IL-3 or the alpha chain of the IL-3 receptor, displayed no greater deficiencies in megakaryocytes or platelets than mpl-deficient animals, suggesting absence of a physiologic role for IL-3 in the residual megakaryocytopoiesis and platelet production in these mice.


2019 ◽  
Vol 75 (11) ◽  
pp. 6349-2019 ◽  
Author(s):  
ANNA CIECIERSKA ◽  
TOMASZ SADKOWSKI ◽  
TOMASZ MOTYL

Postnatal growth and regeneration capacity of skeletal muscles is dependent mainly on adult muscle stem cells called satellite cells. Satellite cells are quiescent mononucleated cells that are normally located outside the sarcolemma within the basal lamina of the muscle fiber. Their activation, which results from injury, is manifested by mobilization, proliferation, differentiation and, ultimately, fusion into new muscle fibers. The satellite cell pool is responsible for the remarkable regenerative capacity of skeletal muscles. Moreover, these cells are capable of self-renewal and can give rise to myogenic progeny.


2019 ◽  
Vol 244 (18) ◽  
pp. 1619-1628 ◽  
Author(s):  
Carmen Wolke ◽  
Sarah Gürtler ◽  
Daniela Peter ◽  
Jens Weingärtner ◽  
Grazyna Domanska ◽  
...  

Vitamin B6 deficiency during pregnancy translates into a severe vitamin B6 deficiency (plasma levels decreased by 97%) in new-born rats. Further, hallmarks are increased (+89%) concentrations of homocysteine, gross changes in gene methylation and expression, and metabolic alterations including lipid metabolism. This study focuses on determining the effects of vitamin B6-deficiency on cardiolipin composition and oxidative phosphorylation in liver. For this purpose, hepatic cardiolipin composition was analyzed by means of LC/MS/MS, and mitochondrial oxygen consumption was determined by using a Clark-type electrode in a rat model of vitamin B6 deficiency. Liver mitochondria from new-born rats with pre-term vitamin B6 deficiency responded with substantial alterations in cardiolipin composition that include the following changes in the amounts of cardiolipin incorporated fatty acids: increase in C16, decrease in C18, decrease in saturated fatty acid, as well as increase in amount of oxidized cardiolipin species. These changes were accompanied by significantly decreased capacity of oxidative phosphorylation. In conclusion, vitamin B6 deficiency in new born rats induces massive alterations of cardiolipin composition and function of liver mitochondria. These findings support the importance of sufficient periconceptional supply of vitamin B6 to prevent vitamin B6 deficiency. Impact statement Vitamin B6 (VitB6) is an active co-enzyme for more than 150 enzymes and is required for a great diversity of biosynthesis and metabolic reactions. There is an increased need for VitB6 during pregnancy and sufficient supply of VitB6 is crucial for the prevention of cleft palate and neural tube defects. We show that liver mitochondria from new-born rats with pre-term VitB6 deficiency respond with substantial alterations in cardiolipin (CL) composition and in the amount of oxidized CL species. These changes are associated with a decrease in the efficiency of oxidative phosphorylation. The results of this study support the significance of sufficient supply of VitB6 during pregnancy (and periconceptional) for diminishing the number of early abortions and minimizing malformation. The established link between VitB6 deficiency, CL composition, and mitochondrial respiration/energy production provides mechanistic insight as to how the VitB6 deficiency translates into the known pathophysiological and clinically relevant conditions.


2020 ◽  
Author(s):  
Jian-Ming Li ◽  
Ying Li ◽  
Zheng-Yi Luo ◽  
Yu-Ying Hu ◽  
Yue-Wei Bi ◽  
...  

Abstract Background Autism spectrum disorder (ASD) is a developmental disorder, and the effective pharmacological treatments for the core autistic symptoms are currently limited. Increasing evidence, particularly that from clinical studies on ASD patients, suggests a functional link between the gut microbiota and the development of ASD. However, the mechanisms linking the gut microbiota with brain dysfunctions (gut-brain axis) in ASD have not yet been full elucidated. Due to its genetic mutations and downregulated expression in patients with ASD, EPHB6, which also plays important roles in gut homeostasis, is generally considered a candidate gene for ASD. Nonetheless, the role and mechanism of EPHB6 in regulating the gut microbiota and the development of ASD are unclear.Results Here, we found that the deletion of EphB6 induced autism-like behavior and disturbed the gut microbiota in mice. More importantly, transplantation of the fecal microbiota from EphB6-deficient mice resulted in autism-like behavior in antibiotic-treated C57BL/6J mice, and transplantation of the fecal microbiota from wild-type mice ameliorated the autism-like behavior in EphB6-deficient mice. At the metabolic level, the disturbed gut microbiota in EphB6-deficient mice led to vitamin B6 and dopamine defects. At the cellular level, the excitation/inhibition (E/I) balance in the medial prefrontal cortex was regulated by gut microbiota-mediated vitamin B6 in EphB6-deficient mice.Conclusions Our study uncovers a key role for the gut microbiota in the regulation of autism-like social behavior by vitamin B6, dopamine and the E/I balance in EphB6-deficient mice, and these findings suggest new strategies for understanding and treating ASD.


2019 ◽  
Vol 47 (5) ◽  
pp. 1393-1404 ◽  
Author(s):  
Thomas Brand

Abstract The Popeye domain-containing gene family encodes a novel class of cAMP effector proteins in striated muscle tissue. In this short review, we first introduce the protein family and discuss their structure and function with an emphasis on their role in cyclic AMP signalling. Another focus of this review is the recently discovered role of POPDC genes as striated muscle disease genes, which have been associated with cardiac arrhythmia and muscular dystrophy. The pathological phenotypes observed in patients will be compared with phenotypes present in null and knockin mutations in zebrafish and mouse. A number of protein–protein interaction partners have been discovered and the potential role of POPDC proteins to control the subcellular localization and function of these interacting proteins will be discussed. Finally, we outline several areas, where research is urgently needed.


JAMA ◽  
1966 ◽  
Vol 198 (8) ◽  
pp. 815-825 ◽  
Author(s):  
G. E. Palade

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Ashley M. Fields ◽  
Kevin Welle ◽  
Elaine S. Ho ◽  
Clementina Mesaros ◽  
Martha Susiarjo

AbstractIn pancreatic islets, catabolism of tryptophan into serotonin and serotonin receptor 2B (HTR2B) activation is crucial for β-cell proliferation and maternal glucose regulation during pregnancy. Factors that reduce serotonin synthesis and perturb HTR2B signaling are associated with decreased β-cell number, impaired insulin secretion, and gestational glucose intolerance in mice. Albeit the tryptophan-serotonin pathway is dependent on vitamin B6 bioavailability, how vitamin B6 deficiency impacts β-cell proliferation during pregnancy has not been investigated. In this study, we created a vitamin B6 deficient mouse model and investigated how gestational deficiency influences maternal glucose tolerance. Our studies show that gestational vitamin B6 deficiency decreases serotonin levels in maternal pancreatic islets and reduces β-cell proliferation in an HTR2B-dependent manner. These changes were associated with glucose intolerance and insulin resistance, however insulin secretion remained intact. Our findings suggest that vitamin B6 deficiency-induced gestational glucose intolerance involves additional mechanisms that are complex and insulin independent.


Genes ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 465
Author(s):  
Colleen A. Mangold ◽  
David P. Hughes

Many organisms are able to elicit behavioral change in other organisms. Examples include different microbes (e.g., viruses and fungi), parasites (e.g., hairworms and trematodes), and parasitoid wasps. In most cases, the mechanisms underlying host behavioral change remain relatively unclear. There is a growing body of literature linking alterations in immune signaling with neuron health, communication, and function; however, there is a paucity of data detailing the effects of altered neuroimmune signaling on insect neuron function and how glial cells may contribute toward neuron dysregulation. It is important to consider the potential impacts of altered neuroimmune communication on host behavior and reflect on its potential role as an important tool in the “neuro-engineer” toolkit. In this review, we examine what is known about the relationships between the insect immune and nervous systems. We highlight organisms that are able to influence insect behavior and discuss possible mechanisms of behavioral manipulation, including potentially dysregulated neuroimmune communication. We close by identifying opportunities for integrating research in insect innate immunity, glial cell physiology, and neurobiology in the investigation of behavioral manipulation.


Author(s):  
Marc Permanyer ◽  
Berislav Bošnjak ◽  
Silke Glage ◽  
Michaela Friedrichsen ◽  
Stefan Floess ◽  
...  

AbstractSignaling via interleukin-2 receptor (IL-2R) is a requisite for regulatory T (Treg) cell identity and function. However, it is not completely understood to what degree IL-2R signaling is required for Treg cell homeostasis, lineage stability and function in both resting and inflammatory conditions. Here, we characterized a spontaneous mutant mouse strain endowed with a hypomorphic Tyr129His variant of CD25, the α-chain of IL-2R, which resulted in diminished receptor expression and reduced IL-2R signaling. Under noninflammatory conditions, Cd25Y129H mice harbored substantially lower numbers of peripheral Treg cells with stable Foxp3 expression that prevented the development of spontaneous autoimmune disease. In contrast, Cd25Y129H Treg cells failed to efficiently induce immune suppression and lost lineage commitment in a T-cell transfer colitis model, indicating that unimpaired IL-2R signaling is critical for Treg cell function in inflammatory environments. Moreover, single-cell RNA sequencing of Treg cells revealed that impaired IL-2R signaling profoundly affected the balance of central and effector Treg cell subsets. Thus, partial loss of IL-2R signaling differentially interferes with the maintenance, heterogeneity, and suppressive function of the Treg cell pool.


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