STEM CELLS AND DEVELOPMENT

Establishment of Periodontal Ligament Stem Cell-like Cells Derived from Feeder-Free Cultured Induced Pluripotent Stem Cells
Yamashita D, Hamano S, Hasegawa D, Sugii H, Itoyama T, Ikeya M and Maeda H
The periodontal ligament (PDL) is a fibrous connective tissue that connects the cementum of the root to the alveolar bone. PDL stem cells (PDLSCs) contained in the PDL can differentiate into cementoblasts, osteoblasts, and PDL fibroblasts, with essential roles in periodontal tissue regeneration. Therefore, PDLSCs are expected to be useful in periodontal tissue regeneration therapy. In a previous study, we differentiated induced pluripotent stem cells (iPSCs) into PDLSC-like cells (iPDLSCs), which expressed PDL-related markers and mesenchymal stem cell (MSC) markers; they also exhibited high proliferation and multipotency. However, the iPSCs used in this differentiation method were cultured on mouse embryonic fibroblasts; thus, they constituted on-feeder iPSCs (OF-iPSCs). Considering the risk of contamination with feeder cell-derived components, iPDLSCs differentiated from OF-iPSCs (ie, OF-iPDLSCs) are unsuitable for clinical applications. In this study, we aimed to obtain PDLSC-like cells from feeder-free iPSCs (FF-iPSCs) using OF-iPDLSC differentiation method. First, we differentiated FF-iPSCs into neural crest cell-like cells (FF-iNCCs) and confirmed that FF-iNCCs expressed NCC markers (eg, Nestin and p75NTR). Then, we cultured FF-iNCCs on human primary PDL cell-derived extracellular matrix for 2 weeks; the resulting cells were named FF-iPDLSCs. FF-iPDLSCs exhibited higher expression of PDL-related and MSC markers compared with OF-iPDLSCs. FF-iPDLSCs also demonstrated proliferation and multipotency in vitro. Finally, we analyzed the ability of FF-iPDLSCs to form periodontal tissue in vivo upon subcutaneous transplantation with β-tricalcium phosphate scaffolds into dorsal tissues of immunodeficient mice. Eight weeks after transplantation, FF-iPDLSCs had formed osteocalcin-positive bone/cementum-like tissues and collagen 1-positive PDL-like fibers. These results suggested that we successfully obtained PDLSC-like cells from FF-iPSCs. Our findings will contribute to the development of novel periodontal regeneration therapies.
The Effects of Different Developmental Stages on Bone Regeneration of Periodontal Ligament Stem Cells and Periodontal Ligament Cell Sheets In Vitro and Vivo
Shao X, Wu F, Song Y, Kong R, Wang S and Wang L
Periodontal ligament stem cells (PDLSCs) have broad applications in tissue engineering and regeneration. However, the function of PDLSCs changes in different microenvironments. This study aimed to explore the effects of different developmental stages on the biological characteristics of PDLSCs. Here, PDLSCs were successfully cultured from the periodontal tissues of various groups, including a group with immature roots, a young group with mature roots, and an aging group with mature roots. By comparing the results of the three experimental groups, we found that the donors with immature roots exhibited the best proliferative ability and osteogenic differentiation, whereas the aging group demonstrated the worst proliferation. The trend for adipogenic differentiation was the opposite to that for osteogenic differentiation. The cell sheet and in vivo experiments revealed that in the immature root group, the cells produced more extracellular matrix and new bone and better absorbed the implant materials. These results indicate that PDLSCs perform various functions at different stages of development. In clinical applications of PDLSCs for periodontal regeneration, donors with incompletely developed roots have stronger biological characteristics.
Generation of Functioning Platelets from Mature Megakaryocytes Derived from CD34 Umbilical Cord Blood Cells
Zhong Z, Chen C, Wang N, Qiu Y, Li X, Liu S, Wu H, Tang X, Fu Y, Chen Q, Guo T, Wei Y and Duan Y
Clinically patients with thrombocytopenia are in urgent need of platelet transfusion, thus it is necessary to produce the platelets in large scale in vitro to meet the clinical needs. In this study, we developed efficient protocol to generate functioning platelets by differentiating umbilical cord blood (CB)-derived CD34 cells into mature megakaryocytes. Under our condition, up to 85% of mature megakaryocytes were generated from CB-derived CD34 cells, and over 75% CD42bCD62p platelets were produced. The megakaryocytes at day 12 after the differentiation had the similar gene expression pattern to natural mature megakaryocytes, and AMPK and insulin signal pathway were activated to inhibit the apoptosis and benefit platelet release. There were up to 72% of the platelets that could bind with PAC1, which is the highest rate of CB CD34 cell-derived platelets to play function to date. The recovery of hemostasis and coagulation was similar in thrombocytopenia mice injected with CB CD34 cell-derived platelets and with human blood-derived platelets, respectively, and it is the first time to demonstrate that human CB CD34 cell-derived platelets were functional . Therefore, our findings open a new avenue to provide an efficient approach to generate functional platelets for clinical applications.
Advancements in Organoid Culture Technologies: Current Trends and Innovations
Ji Y and Sun Y
Organoids have emerged as valuable tools in investigating disease mechanisms, drug efficacy, and personalized medicine due to their capacity to recapitulate crucial aspects of tissue physiology, including cell-cell interactions, heterogeneity, microenvironmental cues, and drug responses. Despite their broad applicability across various research domains, conventional organoid culture methods are plagued by several limitations that hinder research progress. These limitations include the inability to faithfully recreate tissue microenvironments, immune contexts, and vascular systems. Fortunately, ongoing advancements in organoid culture techniques are addressing these shortcomings. In this review, we provide a comprehensive overview of current mainstream organoid culture protocols. By evaluating these protocols, researchers can identify the most suitable experimental methods, thereby optimizing resource allocation and experimental outcomes.
YAP Alleviates Pulmonary Fibrosis Through Promoting Alveolar Regeneration via Modulating the Stemness of Alveolar Type 2 Cells
Wang J, Zhu F, Luo R, Cui Y, Zhang Z, Xu M, Zhao Y, He Y, Yang W, Li N, Zhu Z, Chen Y, Wang T, Jiang X and Lin C
Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease with no cure except transplantation. Abnormal alveolar epithelial regeneration is a key driver of IPF development. The function of Yes1 Associated Transcriptional Regulator (YAP) in alveolar regeneration and IPF pathogenesis remains elusive. Here, we first revealed the activation of YAP in alveolar epithelium 2 cells (AEC2s) from human IPF lungs and fibrotic mouse lungs. Notably, conditional deletion of YAP in mouse AEC2s exacerbated bleomycin-induced pulmonary fibrosis. Intriguingly, we showed in both conditional knockout mice and alveolar organoids that YAP deficiency impaired AEC2 proliferation and differentiation into alveolar epithelium 1 cells (AEC1s). Mechanistically, YAP regulated expression levels of genes associated with cell cycle progression and AEC1 differentiation. Furthermore, overexpression of YAP in vitro promoted cell proliferation. These results indicate the critical role of YAP in alveolar regeneration and IPF pathogenesis. Our findings provide new insights into the regulation of alveolar regeneration and IPF pathogenesis, paving the road for developing novel treatment strategies.
The Construction of Stem Cell-Induced Hepatocyte Model and Its Application in Evaluation of Developmental Hepatotoxicity of Environmental Pollutants
Nijiati N, Wubuli D, Li X, Zhou Z, Julaiti M, Huang P and Hu B
Stem cells, with their ability to self-renew and differentiate into various cell types, are a unique and valuable resource for medical research and toxicological studies. The liver is the most crucial metabolic organ in the human body and serves as the primary site for the accumulation of environmental pollutants. Enrichment with environmental pollutants can disrupt the early developmental processes of the liver and have a significant impact on liver function. The liver comprises a complex array of cell types, and different environmental pollutants have varying effects on these cells. Currently, there is a lack of well-established research models that can effectively demonstrate the mechanisms by which environmental pollutants affect human liver development. The emergence of liver cells and organoids derived from stem cells offers a promising tool for investigating the impact of environmental pollutants on human health. Therefore, this study systematically reviewed the developmental processes of different types of liver cells and provided an overview of studies on the developmental toxicity of various environmental pollutants using stem cell models.
Intrapericardial Administration of Human Pericardial Fluid Cells Improves Cardiac Functions in Rats with Heart Failure
Xu Y, Zhang X, Fu Z, Dong Y, Yu Y, Liu Y, Liu Z, Chen J, Yao Y, Chen Y, Ooi JP, Shaharuddin B, Yang B, Tan JJ and Guo Z
Heart failure (HF) is still the main cause of mortality worldwide. This study investigated the characteristics of human pericardial fluid-derived cells (hPFCs) and their effects in treating doxorubicin (DOX)-induced HF rats through intrapericardial injection. hPFCs were isolated from patients who underwent heart transplantation ( = 5). These cells that primarily expressed SCA-1, NANOG, and mesenchymal markers, CD90, CD105, and CD73, were able to form adipocytes, osteoblasts, and cardiomyocytes in vitro. Passage 3 hPFCs (2.5 × 10 cells/heart) were injected into the pericardial cavity of the DOX-injured rat hearts, significantly improving cardiac functions after 4 weeks. The tracked and engrafted red fluorescent protein-tagged hPFCs coexpressed cardiac troponin T and connexin 43 after 4 weeks in the host myocardium. This observation was also coupled with a significant reduction in cardiac fibrosis following hPFC treatment < 0.0001 vs. untreated). The elevated inflammatory cytokines interleukin (IL)-6, IL-10, and tumor necrosis factor-α in the DOX-treated hearts were found to be significantly reduced ( < 0.001 vs. untreated), while the regional proangiogenic vascular endothelial growth factor A (VEGFA) level was increased in the hPFC-treated group after 4 weeks ( < 0.05 vs. untreated). hPFCs possess stem cell characteristics and can improve the cardiac functions of DOX-induced HF rats after 4 weeks through pericardial administration. The improvements were attributed to a significant reduction in cardiac fibrosis, inflammation, and elevated regional proangiogenesis factor VEGFA, with evidence of cellular engraftment and differentiation in the host myocardium.
Metabolomics Dysfunction in Replicative Senescence of Periodontal Ligament Stem Cells Regulated by AMPK Signaling Pathway
Hu M, Liu R, Chen X, Yan S, Gao J, Zhang Y, Wu D, Sun L, Jia Z, Sun G and Liu D
Periodontal ligament mesenchymal stem cells (PDLSCs) are a promising cell resource for stem cell-based regenerative medicine in dentistry, but they inevitably acquire a senescent phenotype after prolonged in vitro expansion. The key regulators of PDLSCs during replicative senescence remain unclear. Here, we sought to elucidate the role of metabolomic changes in determining the cellular senescence of PDLSCs. PDLSCs were cultured to passages 4, 10, and 20. The senescent phenotypes of PDLSCs were detected, and metabolomics analysis was performed. We found that PDLSCs manifested senescence phenotype during passaging. Metabolomics analysis showed that the metabolism of replicative senescence in PDLSCs varied significantly. The AMP-activated protein kinase (AMPK) signaling pathway was closely related to adenosine monophosphate (AMP) levels. The AMP:ATP ratio increased in senescent PDLSCs; however, the levels of p-AMPK, and decreased with senescence. We treated PDLSCs with an activator of the AMPK pathway (AICAR) and observed that the phosphorylated AMPK level at P20 PDLSCs was partially restored. These data delineate that the metabolic process of PDLSCs is active in the early stage of senescence and attenuated in the later stages of senescence; however, the sensitivity of AMPK phosphorylation sites is impaired, causing senescent PDLSCs to fail to respond to changes in energy metabolism.
Dtx2 Deficiency Induces Ependymo-Radial Glial Cell Proliferation and Improves Spinal Cord Motor Function Recovery
Chen HY, Huang YC, Yeh TH, Chang CW, Shen YJ, Chen YC, Sun MQ and Cheng YC
Traumatic injury to the spinal cord can lead to significant, permanent disability. Mammalian spinal cords are not capable of regeneration; in contrast, adult zebrafish are capable of such regeneration, fully recovering motor function. Understanding the mechanisms underlying zebrafish neuroregeneration may provide useful information regarding endogenous regenerative potential and aid in the development of therapeutic strategies in humans. DELTEX proteins (DTXs) regulate a variety of cellular processes. However, their role in neural regeneration has not been described. We found that zebrafish , encoding Deltex E3 ubiquitin ligase 2, is expressed in ependymo-radial glial cells in the adult spinal cord. After spinal cord injury, the heterozygous mutant fish motor function recovered quicker than that of the wild-type controls. The mutant fish displayed increased ependymo-radial glial cell proliferation and augmented motor neuron formation. Moreover, gene expression, downstream of Notch signaling, increased in Dtx2 mutants. Notch signaling inactivation by dominant-negative Rbpj abolished the increased ependymo-radial glia proliferation caused by Dtx2 deficiency. These results indicate that ependymo-radial glial proliferation is induced by Dtx2 deficiency by activating Notch-Rbpj signaling to improve spinal cord regeneration and motor function recovery.
Stanniocalcin 2 Promotes Neuronal Differentiation in Neural Stem/Progenitor Cells of the Mouse Subventricular Zone Through Activation of AKT Pathway
Guo Z, Zhang H, Jingele X, Yan J, Wang X, Liu Y, Huang T and Liu C
Neural stem/progenitor cells (NSPCs) persist in the mammalian subventricular zone (SVZ) throughout life, responding to various pathophysiological stimuli and playing a crucial role in central nervous system repair. Although numerous studies have elucidated the role of stanniocalcin 2 (STC2) in regulating cell differentiation processes, its specific function in NSPCs differentiation remains poorly understood. Clarifying the role of STC2 in NSPCs is essential for devising novel strategies to enhance the intrinsic potential for brain regeneration postinjury. Our study revealed the expression of STC2 in NSPCs derived from the SVZ of the C57BL/6N mouse. In cultured SVZ-derived NSPCs, STC2 treatment significantly increased the number of Tuj1 and DCX-positive cells. Furthermore, STC2 injection into the lateral ventricle promoted the neuronal differentiation of NSPCs and migration to the olfactory bulb. Conversely, the STC2 knockdown produced the opposite effect. Further investigation showed that STC2 treatment enhanced AKT phosphorylation in cultured NSPCs, whereas STC2 inhibition hindered AKT activation. Notably, the neuronal differentiation induced by STC2 was blocked by the AKT inhibitor GSK690693, whereas the AKT activator SC79 reversed the impact of STC2 knockdown on neuronal differentiation. Our findings indicate that enhancing STC2 expression in SVZ-derived NSPCs facilitates neuronal differentiation, with AKT regulation potentially serving as a key intracellular target of STC2 signaling.
An Endothelial Cell Is Not Simply an Endothelial Cell
Limbu S and McCloskey KE
Endothelial cells (ECs) are a multifaceted component of the vascular system with roles in immunity, maintaining tissue fluid balance, and vascular tone. Dysregulation or dysfunction of ECs can have far-reaching implications, leading pathologies ranging from cardiovascular diseases, such as hypertension and atherosclerosis, ischemia, chronic kidney disease, blood-brain barrier integrity, dementia, and tumor metastasis. Recent advancements in regenerative medicine have highlighted the potential of stem cell-derived ECs, particularly from induced pluripotent stem cells, to treat ischemic tissues, as well as models of vascular integrity. This review summarizes what is known in the generation of ECs with an emphasis on tissue-specific ECs and EC subphenotypes important in the development of targeted cell-based therapies for patient treatment.
Development of Mesenchymal Stem Cell Encoded with Myogenic Gene for Treating Radiation-Induced Muscle Fibrosis
Kim IG, Eom SY, Cho H, Kim Y, Hwang S, Kim H, Seok J, Chung S, Kim HJ and Chung EJ
Radiation therapy (RT) is a typical treatment for head and neck cancers. However, prolonged irradiation of the esophagus can cause esophageal fibrosis due to increased reactive oxygen species and proinflammatory cytokines. The objective of this study was to determine whether myogenic gene-transfected mesenchymal stem cells (MSCs) could ameliorate damage to esophageal muscles in a mouse model of radiation-induced esophageal fibrosis. We cloned esophageal myogenic genes (MyoD, MyoG, and Myf6) using plasmid DNA. Afterward, myogenic genes were transfected into Human Mesenchymal Stem Cells (hMSCs) using electroporation. Gene transfer efficiency, stemness, and myogenic gene profile were examined using flow cytometry, quantitative polymerase chain reaction, and RNA sequencing. In vivo efficacy of gene-transfected hMSCs was demonstrated through histological and gene expression analyses using a radiation-induced esophageal fibrosis animal model. We have confirmed that the gene transfer efficiency was high (∼75%). Pluripotency levels in gene-transfected MSCs were significantly decreased compared with those in the control (vector). Particularly, myogenesis-related genes such as OAS2, OAS3, and HSPA1A were overexpressed in the group transfected with three genes. At 4 weeks after injection, it was found that thickness collagen layer and esophageal muscle in MSCs transfected with all three genes were significantly reduced compared to those in the saline group. Muscularis mucosa was observed prominently in the gene combination group. Moreover, expression levels of myogenin, Myf6, calponin, and SM22α known to be specific markers of esophageal muscles tended to increase in the group transfected with three genes. Therefore, using gene-transfected MSCs has the potential as a promising therapy against radiation-induced esophageal fibrosis.
Modeling Choroideremia Disease with Isogenic Induced Pluripotent Stem Cells
Fonseca AF, Coelho R, da-Silva ML, Lemos L, Hall MJ, Oliveira D, Falcão AS, Tenreiro S, Seabra MC and Antas P
Choroideremia (CHM) is a rare X-linked chorioretinal dystrophy causing progressive vision loss due to mutations in the gene, leading to Rab escort protein 1 loss of function. CHM disease is characterized by a progressive degeneration of the choroid, the retinal pigment epithelium (RPE), and the retina. The RPE is a monolayer of polarized cells that supports photoreceptors, providing nutrients, growth factors, and ions, and removes retinal metabolism waste products, having a central role in CHM pathogenesis. Commonly used models such as ARPE-19 cells do not reproduce accurately the nature of RPE cells. Human induced pluripotent stem cells (hiPSCs) can be differentiated into RPE cells (hiPSC-RPE), which mimic key features of native RPE, being more suited to study retinal diseases. Therefore, we took advantage of hiPSCs to generate new human-based CHM models. Two isogenic hiPSC lines were generated through CRISPR/Cas9: a CHM knock-out line from a healthy donor and a corrected CHM patient line using a knock-in approach. The differentiated hiPSC-RPE lines exhibited critical morphological and physiological characteristics of native RPE, including the presence of the tight junction markers Claudin-19 and Zonula Occludens-1, phagocytosis of photoreceptor outer segments, pigmentation, a postmitotic state, and the characteristic polygonal shape. In addition, all the studied cells were able to form retinal organoids. This work resulted in the establishment of isogenic hiPSC lines, representing a new and important CHM cellular model. To our knowledge, this is the first time that isogenic cell lines have been developed to model CHM disease, providing a valuable tool for studying the mechanisms at the onset of RPE degeneration.
Cleft Palate Induced by Augmented Fibroblast Growth Factor-9 Signaling in Cranial Neural Crest Cells in Mice
Lin C, Liu S, Ruan N, Chen J, Chen Y, Zhang Y and Zhang J
Although enhanced fibroblast growth factor (FGF) signaling has been demonstrated to be crucial in many cases of syndromic cleft palate caused by tongue malposition in humans, animal models that recapitulate this phenotype are limited, and the precise mechanisms remain elusive. Mutations in with the effect of either loss- or gain-of-function effects have been identified to be associated with cleft palate in humans. Here, we generated a mouse model with a transgenic allele specifically activated in cranial neural crest cells, aiming to elucidate the gain-of-function effects of in palatogenesis. We observed cleft palate with 100% penetrance in mutant mice. Further analysis demonstrated that no inherent defects in the morphogenic competence of palatal shelves could be found, but a passively lifted tongue prevented the elevation of palatal shelves, leading to the cleft palate. This tongue malposition was induced by posterior spatial confinement that was exerted by temporomandibular joint (TMJ) dysplasia characterized by a reduction in Sox9+ progenitors within the condyle and a structural decrease in the posterior dimension of the lower jaw. Our findings highlight the critical role of excessive FGF signaling in disrupting spatial coordination during palate development and suggest a potential association between palatal shelf elevation and early TMJ development.
Safety and Potential Efficacy of Expanded Umbilical Cord-Derived Mesenchymal Stromal Cells in Luminal Ulcerative Colitis Patients
Jafar H, Alqudah D, Rahmeh R, Al-Hattab D, Ahmed K, Rayyan R, Abusneinah A, Rasheed M, Rayyan Y and Awidi A
Inflammatory bowel disease (IBD) is characterized by periods of flare-ups and remission. It is likely to be an autoimmune in origin, presenting persistent therapeutic challenges despite current therapies. This study aims to investigate the potential of umbilical cord mesenchymal stromal cells (UCMSCs) in treating ulcerative colitis (UC). This study is a prospective phase 1 pilot, open-label, single-arm, and single-center study. UCMSCs were cultured under current Good Manufacturing Practice (cGMP) conditions and intravenously administered to six patients with UC. Safety and efficacy were evaluated using the Mayo Score/Disease Activity Index. Among the six enrolled adult patients, five completed long-term follow-ups. All exhibited at diagnosis active UC confirmed through comprehensive assessment methods. Each patient received three injections intravenously 2 weeks apart with a dose of 100 million UCMSC each. No significant short-term or intermediate-term adverse events were detected post-UCMSC administration. Long-term follow-up at 12 and 24 months showed sustained safety and no adverse events. Notably, three out of five patients achieved a Mayo score of 0 for UC, maintained at both 12 and 24 months, indicating a highly significant response ( < 0.001). This study demonstrates the safety and potential efficacy of UCMSCs in active UC. However, larger trials are warranted to validate these preliminary findings and to establish the role of UCMSC therapy as an option for managing UC.
Vitamin D3 Improves Adipose Stromal Cell Survival and Human Fat Graft Retention in Xenograft Model
Gavrilescu A, Loder SJ, Ricketts R, Lee P, Ramkumar D, Shaaban B, Elmeanawy A, Vagonis A, Gusenoff JA, Rubin JP and Kokai LE
Adipose stem cells are considered one of the primary drivers of autologous fat graft biological activity and survival. We have previously demonstrated that hormonally active VD3 improved adipose stem cell viability in ex vivo and in vivo fat grafting models. In this study, we evaluated the inactive form of VD3 (cholecalciferol) on adipose stromal cell (ASC) phenotype during hypoxia and the subsequent effect on human fat graft retention in the xenograft model. Lipoaspirate collected from six human donors was used for ex vivo particle culture studies and isolated ASC studies. Adipose particles were treated with increasing doses of VD3 to determine impact on ASC survival. Expanded stromal cells were treated with VD3 during hypoxic culture and assessed for viability, apoptosis, mitochondrial activity, and nitric oxide (NO) release via caspase, DAF-FM, or TMRM. Finally, 40 Nu/J mice receiving bilateral dorsal human lipoaspirate were treated thrice weekly with (1) vehicle control, (2) 50 ng calcitriol, (3) 50 ng VD3, (4) 500 ng VD3, and (5) 5,000 ng VD3 for 12 weeks, = 8 per group. Graft weight, volume, and architecture were analyzed. Adipose particles treated with dose-escalating VD3 had significantly increased ASC viability compared with control ( < 0.01). Under hypoxia, ASCs treated with 1 nM VD3 had significantly greater viability than untreated and pretreated cells ( < 0.01, < 0.01) and significantly lower apoptosis-to-viability ratio ( < 0.01). ASCs pretreated with 1 nM VD3 had significantly lower NO release ( < 0.05) and lower mitochondrial polarization ( < 0.05) compared with controls. In vivo results showed mice receiving 5,000 ng VD3 had significantly greater graft weight ( < 0.05) and volume ( < 0.05) after 12 weeks of treatment compared with controls. Grafts had enhanced neovascularization, intact adipocyte architecture, and absence of oil cysts. VD3 is an over-the-counter nutritional supplement with a known safety profile in humans. Our xenograft model suggests administering VD3 at the time of surgery may significantly improve fat graft retention.
Prostaglandin E2 Induces YAP1 and Agrin Through EP4 in Neonatally-Derived Islet-1+ Stem Cells
Hughes L, Lopez LV and Kearns-Jonker M
Prostaglandin E2 (PGE2) has recently gained attention in the field of regenerative medicine because of the beneficial effects of this molecule on stem cell proliferation and migration. Furthermore, PGE2 has the ability to mitigate immune rejection and fibrosis. In the colon and kidney, PGE2 induces YAP1, a transcription factor critical for cardiac regeneration. Establishing a similar connection in stem cells that can be transplanted in the heart could lead to the development of more effective therapeutics. In this report, we identify the effects of PGE2 on neonatal Islet-1+ stem cells. These stem cells synthesize PGE2, which functions by stimulating the transcription of the extracellular matrix protein Agrin. Agrin upregulates YAP1. Consequently, both YAP1 and Agrin are induced by PGE2 treatment. Our study shows that PGE2 upregulated the expression of both and in Islet-1+ stem cells through the EP4 receptor and stimulated proliferation using the same mechanisms. PGE2 administration further elevated the expression of stemness markers and the matrix metalloproteinase , a key regulator of remodeling in the extracellular matrix post-injury. The expression of PGE2 in neonatal Islet-1+ cells is a factor which contributes to improving the functional efficacy of these cells for cardiac repair.
Direct Water-Soluble Molecules Transfer from Transplanted Bone Marrow Mononuclear Cell to Hippocampal Neural Stem Cells
Okinaka Y, Maeda M, Kataoka Y, Nakagomi T, Doi A, Boltze J, Claussen C, Gul S and Taguchi A
Intravascularly transplanted bone marrow cells, including bone marrow mononuclear cells (BM-MNC) and mesenchymal stem cells, transfer water-soluble molecules to cerebral endothelial cells via gap junctions. After transplantation of BM-MNC, this fosters hippocampal neurogenesis and enhancement of neuronal function. Herein, we report the impact of transplanted BM-MNC on neural stem cells (NSC) in the brain. Surprisingly, direct transfer of water-soluble molecules from transplanted BM-MNC and peripheral mononuclear cells to NSC in the hippocampus was observed already 10 min after cell transplantation, and transfer from BM-MNC to GFAP-positive cortical astrocytes was also observed. In vitro investigations revealed that BM-MNC abolish the expression of hypoxia-inducible factor-1α in astrocytes. We suggest that the transient and direct transfer of water-soluble molecules between cells in circulation and NSC in the brain may be one of the biological mechanisms underlying the repair of brain function.
Stem Cell Division and Its Critical Role in Mammary Gland Development and Tumorigenesis: Current Progress and Remaining Challenges
Zeng P, Shu LZ, Zhou YH, Huang HL, Wei SH, Liu WJ and Deng H
The origin of breast cancer (BC) has traditionally been a focus of medical research. It is widely acknowledged that BC originates from immortal mammary stem cells and that these stem cells participate in two division modes: symmetric cell division (SCD) and asymmetrical cell division (ACD). Although both of these modes are key to the process of breast development and their imbalance is closely associated with the onset of BC, the molecular mechanisms underlying these phenomena deserve in-depth exploration. In this review, we first outline the molecular mechanisms governing ACD/SCD and analyze the role of ACD/SCD in various stages of breast development. We describe that the changes in telomerase activity, the role of polar proteins, and the stimulation of ovarian hormones subsequently lead to two distinct consequences: breast development or carcinogenesis. Finally, gene mutations, abnormalities in polar proteins, modulation of signal-transduction pathways, and alterations in the microenvironment disrupt the balance of BC stem cell division modes and cause BC. Important regulatory factors such as mammalian Inscuteable mInsc, Numb, Eya1, PKCα, PKCθ, p53, and IL-6 also play significant roles in regulating pathways of ACD/SCD and may constitute key targets for future research on stem cell division, breast development, and tumor therapy.
Differentiation, Metabolism, and Cardioprotective Secretory Functions of Human Cardiac Stromal Cells from Ischemic and Endocarditis Patients
Nguyen H, Hsu CC, Meeson A, Oldershaw R, Richardson G, Czosseck A and Lundy DJ
This study investigates the characteristics of cardiac mesenchymal stem cell-like cells (CMSCLCs) isolated from the right atrial appendage of human donors with ischemia and a young patient with endocarditis (NE-CMSCLCs). Typical CMSCLCs from ischemic heart patients were derived from coronary artery bypass grafting procedures and compared against bone marrow mesenchymal stromal cells (BM-MSCs). NE-CMSCLCs had a normal immunophenotype, but exhibited enhanced osteogenic differentiation potential, rapid proliferation, reduced senescence, reduced glycolysis, and lower reactive oxygen species generation after oxidative stress compared with typical ischemic CMSCLCs. These differences suggest a unique functional status of NE-CMSCLCs, influenced by the donor health condition. Despite large variances in their paracrine secretome, NE-CMSCLCs retained therapeutic potential, as indicated by their ability to protect hypoxia/reoxygenation-injured human cardiomyocytes, albeit less effectively than typical CMSCLCs. This research describes a unique cell phenotype and underscores the importance of donor health status in the therapeutic efficacy of autologous cardiac cell therapy.
Differential Secretomes of Processed Adipose Grafts, the Stromal Vascular Fraction, and Adipose-Derived Stem Cells
Carr H, Asaad M, Wu Y, Branch-Brooks C, Zhang Q, Hematti P and Hanson SE
There are multiple methods to prepare lipoaspirate for autologous fat transfer; however, graft retention remains unpredictable. The purpose of this study was to compare the cellular and protein composition of adipose grafts and the stromal vascular fraction (SVF) resulting from three common techniques to prepare adipose grafts. Adipose grafts were harvested from healthy donors and processed via three techniques: centrifugation (C), a single-filter (SF) device, and a double-filtration (DF) system. Part of each graft was analyzed or further processed to isolate the SVF. Cell viability, surface markers, cytokine, and growth factors were compared between the graft and SVF as well as adipose-derived stem cells (ASCs). Overall, we found variations across the three processing techniques and among the graft components (ASCs, SVF, and fat). Cell viability within the grafts was similar (94.6%, 92.3%, and 93.6%; = 0.93). The trend was a greater percentage of ASCs from SF versus DF or centrifugation (6.95%, 4.63%, and 1.93%, respectively, = 0.06). Adipogenic markers (adiponectin and leptin) were similar among all three grafts ( = 0.45). Markers of tissue remodeling were greatest in the SVF compared with fat and ASCs, regardless of processing technique. There was higher relative expression of MMP-9 (2×), Extracellular matrix metalloproteinase inducer (EMMPRIN) (2.5×), endoglin (5×), and IL-8 (1.5×) in the SVF ( < 0.005). Our study identified differences in cytokine expression in adipose grafts and the SVF, particularly in cytokines important in inflammation and wound healing. These secretomes may impact graft retention and fat necrosis and have the potential implications in cell-assisted lipotransfer. There were no significant differences between the final products of any of the processing techniques.