Endothelial Cells Control Muscle Regeneration Through Angiocrine Lactate

2019 ◽  
Author(s):  
Jing Zhang ◽  
Jonathan Muri ◽  
Tatiane Gorski ◽  
Gillian Fitzgerald ◽  
Gommaar D'Hulst ◽  
...  

2021 ◽  
pp. 1-23
Author(s):  
Theret Marine ◽  
Saclier Marielle ◽  
Messina Graziella ◽  
Rossi M.V. Fabio

While skeletal muscle remodeling happens throughout life, diseases that result in its dysfunction are accountable for many deaths. Indeed, skeletal muscle is exceptionally capable to respond to stimuli modifying its homeostasis, such as in atrophy, hypertrophy, regeneration and repair. In particular conditions such as genetic diseases (muscular dystrophies), skeletal muscle’s capacity to remodel is strongly affected and undergoes continuous cycles of chronic damage. This induces scarring, fatty infiltration, as well as loss of contractibility and of the ability to generate force. In this context, inflammation, primarily mediated by macrophages, plays a central pathogenic role. Macrophages contribute as the primary regulators of inflammation during skeletal muscle regeneration, affecting tissue-resident cells such as myogenic cells and endothelial cells, but also fibro-adipogenic progenitors, which are the main source of the fibro fatty scar. During skeletal muscle regeneration their function is tightly orchestrated, while in dystrophies their fate is strongly disturbed, resulting in chronic inflammation. In this review, we will discuss the latest findings on the role of macrophages in skeletal muscle diseases, and how they are regulated.



Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Aurelie S Leroyer ◽  
Teni G Ebrahimian ◽  
Jose Vilar ◽  
Bernard I Levy ◽  
Alain Tedgui ◽  
...  

Postischemic neovascularization is mediated, at least in part, by the homing of progenitor cells to sites of injury and their differentiation into endothelial cells (EC). However, the mechanisms of in situ progenitor differentiation remain for the most part unknown. We hypothesized that miproparticles (MPs) released following ischemia-induced cell activation or apoptosis are the endogenous signal of postischemic vasculogenesis. MPs were detected by electron microscopy as vesicles of 0.1 to 1 μm in diameter in mice ischemic hindlimb muscle, 48hrs after unilateral femoral artery ligation. After isolation by sequential centrifugations, flow cytometry analyses showed that AnnexinV+ MPs concentration in ischemic calf was 3.5-fold higher than in control muscle (1392±406 vs. 394±180 AnnV+MPs/mg, p<0.005) and mainly originated from endothelial cells (47% of MPs are CD144+). MPs isolated from ischemic muscles induced a more potent in vitro bone marrow-mononuclear cells (BM-MNC) differentiation into EPC, than those isolated from control muscle (6.1±1.0% vs. 3.5±0.7% Dil-LDL/BS1lectin+ cells/field, p<0.05). Moreover, MPs isolated from GFP+ ischemic muscles colocalized with differentiated BM-MNC. MPs isolated from atherosclerotic plaque were uneffective whereas those isolated from apoptotic or IL-1 activated EC also promoted BM-MNC differentiation. Interestingly, MPs from ischemic muscles produced more reactive oxygen species and expressed significantly higher levels of NADPH oxidase p47 (6 fold ; p<0.05) and p67 subunits (16 fold ; p<0.005) than those from control, whereas gp91 subunit expression was unchanged. The MPs-induced BM-MNC differentiation was reduced by two fold with MPs isolated from gp91-deficient mice (p<0.05). MPs effect on post-ischemic vasculogenesis and revascularization was examined in the ischemic hindlimb model. MPs isolated from ischemic muscles were injected into ischemic legs in parallel with venous injection of BM-MNC. MPs increased the pro-angiogenic effect of BM-MNC transplantation and this effect was blunted with MPs from gp91−/− mice. These results demonstrate that MPs produced after tissue ischemia stimulate progenitor cell differentiation and subsequently promote postnatal neovascularization.



2020 ◽  
Vol 54 (2) ◽  
pp. 137-139
Author(s):  
Marco Castro ◽  
Jorge Andrade ◽  
Michael Potente


Author(s):  
D. E. Philpott ◽  
A. Takahashi

Two month, eight month and two year old rats were treated with 10 or 20 mg/kg of E. Coli endotoxin I. P. The eight month old rats proved most resistant to the endotoxin. During fixation the aorta, carotid artery, basil arartery of the brain, coronary vessels of the heart, inner surfaces of the heart chambers, heart and skeletal muscle, lung, liver, kidney, spleen, brain, retina, trachae, intestine, salivary gland, adrenal gland and gingiva were treated with ruthenium red or alcian blue to preserve the mucopolysaccharide (MPS) coating. Five, 8 and 24 hrs of endotoxin treatment produced increasingly marked capillary damage, disappearance of the MPS coating, edema, destruction of endothelial cells and damage to the basement membrane in the liver, kidney and lung.



Author(s):  
C. N. Sun ◽  
J. J. Ghidoni

Endothelial cells in longitudinal and cross sections of aortas from 3 randomly selected “normal” mongrel dogs were studied by electron microscopy. Segments of aorta were distended with cold cacodylate buffered 5% glutaraldehyde for 10 minutes prior to being cut into small, well oriented tissue blocks. After an additional 1-1/2 hour period in glutaraldehyde, the tissue blocks were well rinsed in buffer and post-fixed in OsO4. After dehydration they were embedded in a mixture of Maraglas, D.E.R. 732, and DDSA.Aldehyde fixation preserves the filamentous and tubular structures (300 Å and less) for adequate demonstration and study. The functional significance of filaments and microtubules has been recently discussed by Buckley and Porter; the precise roles of these cytoplasmic components remains problematic. Endothelial cells in canine aortas contained an abundance of both types of structures.



Author(s):  
H.D. Geissinger ◽  
C.K. McDonald-Taylor

A new strain of mice, which had arisen by mutation from a dystrophic mouse colony was designated ‘mdx’, because the genetic defect, which manifests itself in brief periods of muscle destruction followed by episodes of muscle regeneration appears to be X-linked. Further studies of histopathological changes in muscle from ‘mdx’ mice at the light microscopic or electron microscopic levels have been published, but only one preliminary study has been on the tibialis anterior (TA) of ‘mdx’ mice less than four weeks old. Lesions in the ‘mdx’ mice vary between different muscles, and centronucleation of fibers in all muscles studied so far appears to be especially prominent in older mice. Lesions in young ‘mdx’ mice have not been studied extensively, and the results appear to be at variance with one another. The degenerative and regenerative aspects of the lesions in the TA of 23 to 26-day-old ‘mdx’ mice appear to vary quantitatively.



Author(s):  
Waykin Nopanitaya ◽  
Raeford E. Brown ◽  
Joe W. Grisham ◽  
Johnny L. Carson

Mammalian endothelial cells lining hepatic sinusoids have been found to be widely fenestrated. Previous SEM studies (1,2) have noted two general size catagories of fenestrations; large fenestrae were distributed randomly while the small type occurred in groups. These investigations also reported that large fenestrae were more numerous and larger in the endothelial cells at the afferent ends of sinusoids or around the portal areas, whereas small fenestrae were more numerous around the centrilobular portion of the hepatic lobule. It has been further suggested that under some physiologic conditions small fenestrae could fuse and subsequently become the large type, but this is, as yet, unproven.We have used a reproducible experimental model of hypoxia to study the ultrastructural alterations in sinusoidal endothelial fenestrations in order to investigate the origin of occurrence of large fenestrae.



Author(s):  
D.J.P. Ferguson ◽  
M. Virji ◽  
H. Kayhty ◽  
E.R. Moxon

Haemophilus influenzae is a human pathogen which causes meningitis in children. Systemic H. influenzae infection is largely confined to encapsulated serotype b organisms and is a major cause of meningitis in the U.K. and elsewhere. However, the pathogenesis of the disease is still poorly understood. Studies in the infant rat model, in which intranasal challenge results in bacteraemia, have shown that H. influenzae enters submucosal tissues and disseminates to the blood stream within minutes. The rapidity of these events suggests that H. influenzae penetrates both respiratory epithelial and endothelial barriers with great efficiency. It is not known whether the bacteria penetrate via the intercellular junctions, are translocated within the cells or carried across the cellular barrier in 'trojan horse' fashion within phagocytes. In the present studies, we have challenged cultured human umbilical cord_vein endothelial cells (HUVECs) with both capsulated (b+) and capsule-deficient (b-) isogenic variants of one strain of H. influenzae in order to investigate the interaction between the bacteria and HUVEC and the effect of the capsule.





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