Nestin(+) stem cells independently contribute to neural remodelling of the ischemic heart

Distribution, contribution and regulation of nestin+ cells

BACKGROUND

Nestin is an intermediate filament first reported in neuroepithelial stem cells. Nestin expression could be found in a variety of tissues throughout all systems of the body, especially during tissue development and tissue regeneration processes.

AIM OF REVIEW

This review aimed to summarize and discuss current studies on the distribution, contribution and regulation of nestin+ cells in different systems of the body, to discuss the feasibility ofusing nestin as a marker of multilineage stem/progenitor cells, and better understand the potential roles of nestin+ cells in tissue development, regeneration and pathological processes.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review highlights the potential of nestin as a marker of multilineage stem/progenitor cells, and as a key factor in tissue development and tissue regeneration. The article discussed the current findings, limitations, and potential clinical implications or applications of nestin+ cells. Additionally, it included the relationship of nestin+ cells to other cell populations. We propose potential future research directions to encourage further investigation in the field.

JCAD expression and localization in human blood endothelial cells

Background

Junctional Cadherin 5 Associated (JCAD) is an endothelial, cell-cell junction protein, and its expression is associated with cardiovascular diseases including atherosclerosis and hypertension. However, to date, there are few studies confirming JCAD expression and precise localization in human tissues by immunohistochemical staining.

Methods

JCAD expression and localization was assessed in four human submandibular gland (SMG) specimens by immunohistochemical staining. One specimen of SMG with sialoadenitis was accompanied by severe inflammation and fibrosis, while the other was largely normal. Other two SMGs were accompanied by severe fibrosis because of irradiation.

Results

Immunohistochemical analysis of human SMGs revealed JCAD localization at the blood endothelial cell-cell junctions. JCAD expression was more evident in microvessels and arteries in areas affected by inflammation.

Conclusions

The localization of JCAD at endothelial cell-cell junctions was confirmed in human tissues. JCAD expression may be affected by pathological conditions.

Cardiac Nestin+ Mesenchymal Stromal Cells Enhance Healing of Ischemic Heart through Periostin-Mediated M2 Macrophage Polarization

Mesenchymal stromal cells (MSCs) show potential for treating cardiovascular diseases, but their therapeutic efficacy exhibits significant heterogeneity depending on the tissue of origin. This study sought to identify an optimal source of MSCs for cardiovascular disease therapy. We demonstrated that Nestin was a suitable marker for cardiac MSCs (Nes⁺cMSCs), which were identified by their self-renewal ability, tri-lineage differentiation potential, and expression of MSC markers. Furthermore, compared with bone marrow-derived MSCs (Nes⁺bmMSCs) or saline-treated myocardial infarction (MI) controls, intramyocardial injection of Nes⁺cMSCs significantly improved cardiac function and decreased infarct size after acute MI (AMI) through paracrine actions, rather than transdifferentiation into cardiac cells in infarcted heart. We further revealed that Nes⁺cMSC treatment notably reduced pan-macrophage infiltration while inducing macrophages toward an anti-inflammatory M2 phenotype in ischemic myocardium. Interestingly, Periostin, which was highly expressed in Nes⁺cMSCs, could promote the polarization of M2-subtype macrophages, and knockdown or neutralization of Periostin remarkably reduced the therapeutic effects of Nes⁺cMSCs by decreasing M2 macrophages at lesion sites. Thus, the present work systemically shows that Nes⁺cMSCs have greater efficacy than do Nes⁺bmMSCs for cardiac healing after AMI, and that this occurs at least partly through Periostin-mediated M2 macrophage polarization.

The addition of human iPS cell-derived neural progenitors changes the contraction of human iPS cell-derived cardiac spheroids

BACKGROUND

We havebeen attempting to use cardiac spheroids to construct three-dimensional contractilestructures for failed hearts. Recent studies have reported that neuralprogenitors (NPs) play significant roles in heart regeneration. However, theeffect of NPs on the cardiac spheroid has not yet been elucidated.

OBJECTIVE

This studyaims to demonstrate the influence of NPs on the function of cardiac spheroids.

METHODS

Thespheroids were constructed on a low-attachment-well plate by mixing humaninduced pluripotent stem (hiPS) cell-derived cardiomyocytes and hiPScell-derived NPs (hiPS-NPs). The ratio of hiPS-NPs was set at 0%, 10%, 20%,30%, and 40% of the total cell number of spheroids, which was 2500. The motionwas recorded, and the fractional shortening and the contraction velocity weremeasured.

RESULTS

Spheroidswere formed within 48 h after mixing the cells, except for the spheroidscontaining 0% hiPS-NPs. Observation at day 7 revealed significant differencesin the fractional shortening (analysis of variance; p = 0.01). The bestfractional shortening was observed with the spheroids containing 30% hiPS-NPs.Neuronal cells were detected morphologically within the spheroids under aconfocal microscope.

CONCLUSION

Theaddition of hiPS-NPs influenced the contractile function of the cardiacspheroids. Further studies are warranted to elucidate the underlying mechanism.

The Biological Role of Nestin(+)-Cells in Physiological and Pathological Cardiovascular Remodeling

The intermediate filament protein nestin was identified in diverse populations of cells implicated in cardiovascular remodeling. Cardiac resident neural progenitor/stem cells constitutively express nestin and following an ischemic insult migrate to the infarct region and participate in angiogenesis and neurogenesis. A modest number of normal adult ventricular fibroblasts express nestin and the intermediate filament protein is upregulated during the progression of reparative and reactive fibrosis. Nestin depletion attenuates cell cycle re-entry suggesting that increased expression of the intermediate filament protein in ventricular fibroblasts may represent an activated phenotype accelerating the biological impact during fibrosis. Nestin immunoreactivity is absent in normal adult rodent ventricular cardiomyocytes. Following ischemic damage, the intermediate filament protein is induced in a modest population of pre-existing adult ventricular cardiomyocytes bordering the peri-infarct/infarct region and nestin⁽⁺⁾-ventricular cardiomyocytes were identified in the infarcted human heart. The appearance of nestin⁽⁺⁾-ventricular cardiomyocytes post-myocardial infarction (MI) recapitulates an embryonic phenotype and depletion of the intermediate filament protein inhibits cell cycle re-entry. Recruitment of the serine/threonine kinase p38 MAPK secondary to an overt inflammatory response after an ischemic insult may represent a seminal event limiting the appearance of nestin⁽⁺⁾-ventricular cardiomyocytes and concomitantly suppressing cell cycle re-entry. Endothelial and vascular smooth muscle cells (VSMCs) express nestin and upregulation of the intermediate filament protein may directly contribute to vascular remodeling. This review will highlight the biological role of nestin⁽⁺⁾-cells during physiological and pathological remodeling of the heart and vasculature and discuss the phenotypic advantage attributed to the intermediate filament protein.

Transplantation of mesenchymal stem cells promotes tissue regeneration in a glaucoma model through laser-induced paracrine factor secretion and progenitor cell recruitment

Among bone marrow cells, hematopoietic and mesenchymal components can contribute to repair damaged organs. Such cells are usually used in acute diseases but few options are available for the treatment of chronic disorders. In this study, we have used a laser-induced model of open angle glaucoma (OAG) to evaluate the potential of bone marrow cell populations and the mechanisms involved in tissue repair. In addition, we investigated laser-induced tissue remodeling as a method of targeting effector cells into damaged tissues. We demonstrate that among bone marrow cells, mesenchymal stem cells (MSC) induce trabecular meshwork regeneration. MSC injection into the ocular anterior chamber leads to far more efficient decrease in intraocular pressure (IOP) (p < .001) and healing than hematopoietic cells. This robust effect was attributable to paracrine factors from stressed MSC, as injection of conditioned medium from MSC exposed to low but not to normal oxygen levels resulted in an immediate decrease in IOP. Moreover, MSC and their secreted factors induced reactivation of a progenitor cell pool found in the ciliary body and increased cellular proliferation. Proliferating cells were observed within the chamber angle for at least 1 month. Laser-induced remodeling was able to target MSC to damaged areas with ensuing specific increases in ocular progenitor cells. Thus, our results identify MSC and their secretum as crucial mediators of tissue repair in OAG through reactivation of local neural progenitors. In addition, laser treatment could represent an appealing strategy to promote MSC-mediated progenitor cell recruitment and tissue repair in chronic diseases.

Nestin expression in end-stage disease in dystrophin-deficient heart: implications for regeneration from endogenous cardiac stem cells

Nestin(+) cardiac stem cells differentiate into striated cells following myocardial infarct. Transplantation of exogenous stem cells into myocardium of a murine model for Duchenne muscular dystrophy (DMD) increased proliferation of endogenous nestin(+) stem cells and resulted in the appearance of nestin(+) striated cells. This correlated with, and may be responsible for, prevention of dilated cardiomyopathy. We examined nestin(+) stem cells in the myocardium of dystrophin/utrophin-deficient (mdx/utrn(-/-)) mice, a model for DMD. We found that 92% of nestin(+) interstitial cells expressed Flk-1, a marker present on cardiac progenitor cells that differentiate into the cardiac lineage, and that a subset expressed Sca-1, present on adult cardiac cells that become cardiomyocytes. Nestin(+) interstitial cells maintained expression of Flk-1 but lost Sca-1 expression with age and were present in lower numbers in dystrophin-deficient heart than in wild-type heart. Unexpectedly, large clusters of nestin(+) striated cells ranging in size from 20 to 250 cells and extending up to 500 μm were present in mdx/utrn(-/-) heart near the end stage of disease. These cells were also present in dystrophin-deficient mdx/utrn(+/-) and mdx heart but not wild-type heart. Nestin(+) striated cells expressed cardiac troponin I, desmin, and Connexin 43 and correlated with proinflammatory CD68(+) macrophages. Elongated nestin(+) interstitial cells with striations were observed that did not express Flk-1 or the late cardiac marker cardiac troponin I but strongly expressed the early cardiac marker desmin. Nestin was also detected in endothelial and smooth muscle cells. These data indicate that new cardiomyocytes form in dystrophic heart, and nestin(+) interstitial cells may generate them in addition to other cells of the cardiac lineage.

The neurogenic response of cardiac resident nestin(+) cells was associated with GAP43 upregulation and abrogated in a setting of type I diabetes

Background

Cardiac nestin⁽⁺⁾ cells exhibit properties of a neural progenitor/stem cell population characterized by the de novo synthesis of neurofilament-M in response to ischemic injury and 6-hydroxydopamine administration. The induction of growth associated protein 43 (GAP43) was identified as an early event of neurogenesis. The present study tested the hypothesis that the de novo synthesis of neurofilament-M by nestin⁽⁺⁾ cells was preceded by the transient upregulation of GAP43 during the acute phase of reparative fibrosis in the infarcted male rat heart. Secondly, a seminal feature of diabetes is impaired wound healing secondary to an inadequate neurogenic response. In this regard, an additional series of experiments tested the hypothesis that the neurogenic response of cardiac nestin⁽⁺⁾ cells was attenuated in a setting of type I diabetes.

Methods

The neurogenic response of cardiac nestin⁽⁺⁾ cells was examined during the early phase of reparative fibrosis following permanent ligation of the left anterior descending coronary artery in the adult male rat heart. The experimental model of type I diabetes was created following a single injection of streptozotocin in adult male rats. The impact of a type I diabetic environment on the neurogenic response of cardiac nestin⁽⁺⁾ cells was examined during myocardial infarction and following the administration of 6-hydroxydopamine.

Results

During the early phase of scar formation/healing, the density of GAP43/nestin⁽⁺⁾ fibres innervating the peri-infarct/infarct region was significantly increased, whereas neurofilament-M/nestin⁽⁺⁾ fibres were absent. With ongoing scar formation/healing, a temporal decrease of GAP43/nestin⁽⁺⁾ fibre density and a concomitant increase in the density of innervating neurofilament-M/nestin⁽⁺⁾ fibres were observed. The neurogenic response of cardiac nestin⁽⁺⁾ cells during scar formation/healing was inhibited following the superimposition of type I diabetes. The de novo synthesis of neurofilament-M by nestin⁽⁺⁾ cells after 6-hydroxydopamine administration was likewise attenuated in the heart of type I diabetic rats whereas the density of GAP43/nestin⁽⁺⁾ fibres remained elevated.

Conclusion

The transient upregulation of GAP43 apparently represents a transition event during the acquisition of a neuronal-like phenotype and a type I diabetic environment attenuated the neurogenic response of cardiac nestin⁽⁺⁾ cells to ischemia and 6-hydroxydopamine.

Nestin+ cells and healing the infarcted heart

Scar formation following an ischemic insult to the heart is referred to as reparative fibrosis and represents an essential physiological response to heal the damaged myocardium. The biological events of reparative fibrosis include inflammation, the deposition of collagen by myofibroblasts, sympathetic innervation, and angiogenesis. Several studies have further reported that scar formation was associated with the recruitment of neural crest-derived cardiac resident nestin(+) cells that display characteristics consistent with a neural progenitor/stem cell phenotype. During the reparative fibrotic response, these nestin(+) cells participate in neural remodeling and represent a novel cellular substrate of angiogenesis. In addition, a subpopulation of nestin(+) cells identified in the normal heart expressed cardiac progenitor transcriptional factors and may directly contribute to myocardial regeneration following ischemic damage. Nestin protein was also detected in endothelial cells of newly formed blood vessels in the scar and may represent a marker of revascularization. Lastly, nestin was induced in a subpopulation of smooth muscle α-actin(+) scar-derived myofibroblasts, and the expression of the intermediate filament protein may provide a proliferative advantage. Collectively, these data demonstrate that diverse populations of nestin(+) cells participate in cardiac wound healing.