scholarly journals Natural Compounds and PCL Nanofibers: A Novel Tool to Counteract Stem Cell Senescence

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1415
Author(s):  
Emanuela Bellu ◽  
Sara Cruciani ◽  
Giuseppe Garroni ◽  
Francesca Balzano ◽  
Rosanna Satta ◽  
...  

Tissue homeostasis mainly depends on the activity of stem cells to replace damaged elements and restore tissue functions. Within this context, mesenchymal stem cells and fibroblasts are essential for maintaining tissue homeostasis in skin, in particular in the dermis. Modifications in collagen fibers are able to affect stem cell features. Skin properties can be significantly reduced after injuries or with aging, and stem cell niches, mainly comprising extracellular matrix (ECM), may be compromised. To this end, specific molecules can be administrated to prevent the aging process induced by UV exposure in the attempt to maintain a youngness phenotype. NanoPCL-M is a novel nanodevice able to control delivery of Mediterranean plant myrtle (Myrtus communis L.) extracts. In particular, we previously described that myrtle extracts, rich in bioactive molecules and nutraceuticals, were able to counteract senescence in adipose derived stem cells. In this study, we analyzed the effect of NanoPCL-M on skin stem cells (SSCs) and dermal fibroblasts in a dynamic cell culture model in order to prevent the effects of UV-induced senescence on proliferation and collagen depot. The BrdU assay results highlight the significantly positive effect of NanoPCL-M on the proliferation of both fibroblasts and SSCs. Our results demonstrate that-M is able to preserve SSCs features and collagen depot after UV-induced senescence, suggesting their capability to retain a young phenotype.


2020 ◽  
Vol 21 (5) ◽  
pp. 1638 ◽  
Author(s):  
Emilia Di Giovanni ◽  
Silvia Buonvino ◽  
Ivano Amelio ◽  
Sonia Melino

The endogenous gasotransmitter H2S plays an important role in the central nervous, respiratory and cardiovascular systems. Accordingly, slow-releasing H2S donors are powerful tools for basic studies and innovative pharmaco-therapeutic agents for cardiovascular and neurodegenerative diseases. Nonetheless, the effects of H2S-releasing agents on the growth of stem cells have not been fully investigated. H2S preconditioning can enhance mesenchymal stem cell survival after post-ischaemic myocardial implantation; therefore, stem cell therapy combined with H2S may be relevant in cell-based therapy for regenerative medicine. Here, we studied the effects of slow-releasing H2S agents on the cell growth and differentiation of cardiac Lin− Sca1+ human mesenchymal stem cells (cMSC) and on normal human dermal fibroblasts (NHDF). In particular, we investigated the effects of water-soluble GSH–garlic conjugates (GSGa) on cMSC compared to other H2S-releasing agents, such as Na2S and GYY4137. GSGa treatment of cMSC and NHDF increased their cell proliferation and migration in a concentration dependent manner with respect to the control. GSGa treatment promoted an upregulation of the expression of proteins involved in oxidative stress protection, cell–cell adhesion and commitment to differentiation. These results highlight the effects of H2S-natural donors as biochemical factors that promote MSC homing, increasing their safety profile and efficacy after transplantation, and the value of these donors in developing functional 3D-stem cell delivery systems for cardiac muscle tissue repair and regeneration.



2020 ◽  
Author(s):  
Najme Khorasani ◽  
Mehdi Sadeghi ◽  
Abbas Nowzari-Dalini

Stem cells, with their capacity to self-renew and to differentiate to more specialized cell types, play a key role to maintain homeostasis in adult tissues. To investigate how, in the dynamic stochastic environment of a tissue, non-genetic diversity and the precise balance between proliferation and differentiation are achieved, it is necessary to understand the molecular mechanisms of the stem cells in decision making process. By focusing on the impact of stochasticity, we proposed a computational model describing the regulatory circuitry as a tri-stable dynamical system to reveal the mechanism which orchestrate this balance. Our model explains how the distribution of noise in genes, linked to the cell regulatory networks, controls cell decision-making to maintain homeostatic state. The noise control over tissue homeostasis is achieved by regulating the probability of differentiation and self-renewal through symmetric and/or asymmetric cell divisions. Our model reveals, when mutations due to the replication of DNA in stem cell division, are inevitable, how mutations contribute to either aging gradually or the development of cancer in a short period of time. Furthermore, our model sheds some light on the impact of more complex regulatory networks on the system robustness against perturbations.



Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 547-547
Author(s):  
Julia Kirshner ◽  
Kyle J. Thulien ◽  
Lorri D. Martin ◽  
Carina Debes Marun ◽  
Tony Reiman ◽  
...  

Abstract Bone marrow (BM), a site of hematopoiesis, is a multicellular tissue with a complex architecture. Multiple myeloma (MM) is an incurable plasma cell malignancy where even patients in remission succumb to an inevitable relapse. While considerable progress has been made towards understanding and treating MM, to date, there is no culture system which can recapitulate the complex interactions within the BM microenvironment. Current failure to grow the MM clone within the context of human microenvironment hampers progress into the understanding of the biology of MM and design of biologically relevant therapies. Here we present an in vitro three-dimensional (3-D) tissue culture model which recapitulates the human BM microenvironment allowing for the growth and expansion of the MM clone. Cells from the BM aspirates are grown in a fibronectin, laminin and collagen rich ECM designed to reconstruct in vitro endosteum and central marrow, mimicking the in vivo microenvironment of the BM. Proliferation and redistribution of cells within reconstructed ECM results in stratification of the culture, mimicking the in vivo condition where cells occupy individual niches. Cellular composition of the culture is maintained in accordance with the proliferation properties of the BM where osteoblasts, osteoclasts, adipocytes and stromal cells differentiate along with the full complement of the hematopoietic cells. BM cultures from normal donors are well-organized with osteoclasts and hematopoietic cells occupying distinct positions in the ECM. In contrast, reconstructed BM from MM patients is disorganized in 3-D where osteoclasts intermingle with the hematopoietic compartment. The MM malignant clone is expanded in 3-D cultures as measured by real-time quantitative PCR (rqPCR) for genomic clonotypic VDJ sequences. Malignant B and plasma cells proliferate in these cultures and FISH analysis reveals that their progeny harbor chromosomal abnormalities identical to those that mark the malignant clone prior to culture. Preclinical testing of emerging therapeutics targeted for multiple myeloma is hindered by the failure of the current models to sustain growth of the myeloma clone. In the 3-D culture, myeloma clone expands within its native environment providing an ideal preclinical model where conventional (Melphalan) and novel (Velcade) therapeutics efficiently and selectively kill their target cells. In the 3-D BM culture model, non-proliferating, label retaining cells (LRC) concentrate at a putative endosteum-marrow junction, where hematopoietic stem cells have been shown to localize in vivo, suggesting that the drug-resistant myeloma stem cells localize to the endosteal niche. In a colony-forming assay, drug-resistant LRC purified from the 3-D cultures form clonal colonies composed of malignant cells with patient specific clonotypic VDJ sequences. Recapitulation of the BM architecture in vitro is a first step towards the identification and therapeutic targeting of the elusive myeloma stem cell.



2016 ◽  
Vol 95 (13) ◽  
pp. 1445-1451 ◽  
Author(s):  
R. Yang ◽  
Y. Liu ◽  
S. Shi

Hydrogen sulfide (H2S) has long been known as a toxic gas. However, recently accumulated evidence suggests that H2S contributes to a variety of physiologic and pathologic processes. Endogenous H2S production is regulated by multiple enzymes that are differentially expressed in the cardiovascular, neuronal, immune, renal, respiratory, gastrointestinal, reproductive, liver, and endocrine systems. Alteration of H2S metabolism may affect multiple signaling pathways and tissue homeostasis. The growing number of diverse targets for which H2S serves as a gasotransmitter has been extensively reviewed elsewhere. In this review, the authors discuss current emerging evidence that H2S regulates mesenchymal stem cell and T-cell functions.



2017 ◽  
Vol 313 (5) ◽  
pp. H896-H902 ◽  
Author(s):  
Deana M. Apple ◽  
Erzsebet Kokovay

Neural stem cells (NSCs) persist throughout life in the dentate gyrus and the ventricular-subventricular zone, where they continuously provide new neurons and some glia. These cells are found in specialized niches that regulate quiescence, activation, differentiation, and cell fate choice. A key aspect of the regulatory niche is the vascular plexus, which modulates NSC behavior during tissue homeostasis and regeneration. During aging, NSCs become depleted and dysfunctional, resulting in reduced neurogenesis and poor brain repair. In this review, we discuss the emerging evidence that changes in the vascular niche both structurally and functionally contribute to reduced neurogenesis during aging and how this might contribute to reduced plasticity and repair in the aged brain.



2018 ◽  
Author(s):  
Daniel Jun-Kit Hu ◽  
Heinrich Jasper

AbstractHomeostasis in high-turnover tissues depends on precise yet plastic regulation of stem cell daughter fates. In Drosophila, intestinal stem cells (ISCs) respond to unknown signals to switch from asymmetric to symmetric divisions during feeding-induced growth. Here, we show that this switch is controlled by dynamic reorientation of mitotic spindles by a Jun-N-terminal Kinase (JNK) / Wdr62 / Kif1a interaction. JNK promotes Wdr62 localization at the spindle and represses transcription of the kinesin Kif1a. This activity of JNK results in over-abundance of symmetric divisions in stress conditions, and contributes to the loss of tissue homeostasis in the aging animal. Restoring normal ISC spindle orientation by perturbing the JNK/Wdr62/Kif1a axis is sufficient to improve intestinal physiology and extend lifespan. Our findings reveal a critical role for the dynamic control of SC spindle orientation in epithelial maintenance.



2015 ◽  
Vol 10s1 ◽  
pp. BMI.S20057 ◽  
Author(s):  
Prafulla Chandra ◽  
Sang Jin Lee

The innate ability of stem cells to self-renew and differentiate into multiple cell types makes them a promising source for tissue engineering and regenerative medicine applications. Their capacity for self-renewal and differentiation is largely influenced by the combination of physical, chemical, and biological signals found in the stem cell niche, both temporally and spatially. Embryonic and adult stem cells are potentially useful for cell-based approaches; however, regulating stem cell behavior remains a major challenge in their clinical use. Most of the current approaches for controlling stem cell fate do not fully address all of the complex signaling pathways that drive stem cell behaviors in their natural microenvironments. To overcome this limitation, a new generation of biomaterials is being developed for use as three-dimensional synthetic microenvironments that can mimic the regulatory characteristics of natural extracellular matrix (ECM) proteins and ECM-bound growth factors. These synthetic microenvironments are currently being investigated as a substrate with surface immobilization and controlled release of bioactive molecules to direct the stem cell fate in vitro, as a tissue template to guide and improve the neo-tissue formation both in vitro and in vivo, and as a delivery vehicle for cell therapy in vivo. The continued advancement of such an intelligent biomaterial system as the synthetic extracellular microenvironment holds the promise of improved therapies for numerous debilitating medical conditions for which no satisfactory cure exists today.



2019 ◽  
Vol 116 (52) ◽  
pp. 26591-26598 ◽  
Author(s):  
Young V. Kwon ◽  
Bingqing Zhao ◽  
Chiwei Xu ◽  
Jiae Lee ◽  
Chiao-Lin Chen ◽  
...  

Translationally controlled tumor protein (TCTP) is a highly conserved protein functioning in multiple cellular processes, ranging from growth to immune responses. To explore the role of TCTP in tissue maintenance and regeneration, we employed the adultDrosophilamidgut, where multiple signaling pathways interact to precisely regulate stem cell division for tissue homeostasis. Tctp levels were significantly increased in stem cells and enteroblasts upon tissue damage or activation of the Hippo pathway that promotes regeneration of intestinal epithelium. Stem cells with reduced Tctp levels failed to proliferate during normal tissue homeostasis and regeneration. Mechanistically, Tctp forms a complex with multiple proteins involved in translation and genetically interacts with ribosomal subunits. In addition, Tctp increases both Akt1 protein abundance and phosphorylation in vivo. Altogether, Tctp regulates stem cell proliferation by interacting with key growth regulatory signaling pathways and the translation process in vivo.



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