Cardiac progenitors cellsfor vascular repair
Cardiac progenitors cellsfor vascular repair
The heart is the first functional organ to develop, and
cardiomyocytes (cardiac muscle cells) are the essentialand specific-cell type that supports its function during
the entire lifespan, being highly resistant to cell damage
and aging. Cardiomyocytes occupy ≈ 80% of the
volume of mammalian heart, however, they are relatively few in total number compared with non-myocyte
cells (endothelial cells, smooth muscle cells, fibroblasts;
≈ 70% of total cardiac cells) [1]. Both myocytes and
non-myocytes respond to physiological and pathological insults and their maladaptive responses are linked
with the pathogenesis of the cardiac tissue.
During the last decade, various studies have identified
cardiac progenitor-like cells, including immature
cardiomyocytes, that contribute to the low cardiomyocyte turnover (< 2% per year), decreasing their
contribution in an age-dependent manner. While cardiac
regenerative response is effective in embryo and
neonatal period (until 7th day after birth), the
regeneration is particularly limited from adolescence
where ischemic injury lead to the formation of a fibrotic
scar and to the reduction in the heart's pumping capacity
in mice (reviewed in [2]).
The majority of the research in the field of cardiac
regeneration have been focused on limiting the death of
cardiomyocytes and on looking for the source of de
novo cardiomyocytes. Despite the remarkable exchange
rate of endothelial cells in adult heart (>15% per year)
and their essential functions, the cellular source of
mature endothelial cells in homeostasis and after injury
is not characterized. He et al. traced adult cardiac
endothelial cells using a genetic lineage-tracing strategy
based on fluorochrome expression. Lineage dilution
analysis based on the presence or absence of fluorochrome-positive endothelial cells showed that preexisting endothelium (or endothelial-related cells)
mediated the neovascularization after infarction [3]. It is
important to note that these lineage-tracing experiments
were realized based on one endothelial-related gene
(cd31, cdh5) whose expression is not only restricted to
mature endothelial cells. Therefore, it would be possible
that cardiac progenitors which express endothelialrelated genes could mediate the neovascularization response to myocardial infarction.
In this context, several studies have found cardiac progenitor cells located along cardiac vasculature such as Sca1+
adventitial and Gli1+
fibroblast-progenitor cells
[4]. We recently identified a cell population with adult
cardiac progenitor characteristics that expresses high
level of BMI1 (B lymphoma Mo-MLV insertion region
1 homolog) protein [5]. Polycomb complex BMI1
expression is widely linked to the regenerative capacity
of adult tissues and identifies cells with progenitorrelated characteristics in several tissues. In the
mammalian heart, Bmi1+
cardiac progenitors are a
heterogeneous cell population (≈1x105
cells/ adult
heart) located in perivascular position that contributes to
the three main cardiac cell lineages in homeostasis,
increasing this contribution after several types of injury
[6, 7]. Surprisingly, genetic ablation of Bmi1+
cardiac
progenitors in homeostasis did not provoke cardiac
dysfunction or mice death, probably due to cell
plasticity events as showed in other tissue adult stem
cells. The role of Bmi1+
progenitor cells, however,
became essential in the neovascularization process after
myocardial infarction (from 15-days to 2-months),
contributing up to 20% of new endothelial cells.
Genetic ablation of Bmi1+
progenitors before infarction
confirmed that they are necessary for cardiac physiological remodeling and their absence led to cardiac
dysfunction and increased mice death [8].
Cardiac progenitors cellsfor vascular repair
Diego Herrero and Antonio Bernad
www.aging‐us.com AGING 2019, Vol. 11, No. 5
Figure 1. Lineage‐specific cardiac progenitor cells. Overall,
our results suggest that the aging and pathological damage of
Bmi1+ cardiac progenitors could play an important role in heart
aging, exacerbating certain pathological responses. Stimulation
of endogenous Bmi1+ cardiac progenitor cells in the infarcted
myocardium would help counteract the pathological remodeling
by sustaining injury‐induced neovascularization. https://www.aging-us.com/issue/v11i5
When public speak of contemporary medicine, accuracy plays one of the most significant roles and human lives are directly dependent on it. Likewise, any researches pertaining to medicine are required to comply with the top standards. The issue nowadays is that any results of researches can be published online and used as a reference without being properly verified and validated. Mikhail (Misha) Blagosklonny of Oncotarget clearly understood this challenge and attempted to create an alternative solution. That’s how a weekly oncology-focused research journal named “Oncotarget” has been founded back in 2010. The major principle of this journal is related to Altmetric scores that are used as a quality indicator. That helps both readers and authors to verify publications with Altmetric Article Reports that create “real-time feedback containing data summary related to a particular publication.” Oncotarget website has a complete publications list with respective scores above 100 as well as reports mentioned above. Mikhail (Misha) Blagosklonny proud to share his new approach and hopes it provides the required assistance to anybody, who has interest in oncology.
“A diagnostic autoantibody signature for primary cutaneous melanoma” has the Altmetric score of 594. This article was released back in 2018 by Oncotarget and written by different experts from Hollywood Private Hospital, Edith Cowan University, Dermatology Specialist Group, St. John of God Hospital and The University of Western Australia. The introduction of the study discusses “recent data shows that Australians are four times more likely to develop a cancer of the skin than any other type of cancer”, and provides an insight on melanoma that “is curable by surgical excision in the majority of cases, if detected at an early stage.”
The article has got an Altmetric score of 594. Mikhail (Misha) Blagosklonny realizes that majority of readers are aiming to comprehend the very meaning of it. Based on the Altmetric website, the score indicates “how many people have been exposed to and engaged with a scholarly output.” Hereby, the article about melanoma, was used for citations in different news articles 69 times. Moreover, it was quoted in 2 online blogs, as well as 25 Tweets on Twitter and 1 Facebook post. FOX23 of Tulsa, Oklahoma has headlined their report on July 20, 2018 as “New blood test could detect skin cancer early”, using the main content of Australia study
Another Oncotarget’s study with a top score of 476, is “Biomarkers for early diagnosis of malignant mesothelioma: Do we need another moon-shot,”. This study has appeared in 60 news stories, 1 online blog post and 6 Twitter posts. The majority of public may have seen a concise overview only, however those who visit Mikhail (Misha) Blagosklonny at Oncotarget, do receive helpful scientific facts. Oncotarget is proud to have the ability to share with online readers this highly appreciated and high-quality information, that is trustworthy and reliable.
Comments
Post a Comment