Mikroglia bei Alzheimer-Demenz

2014 ◽  
Vol 33 (11) ◽  
pp. 797-804
Author(s):  
J. Wiltfang
Keyword(s):  
Bone Marrow ◽  
Beta Amyloid ◽  
Beclin 1 ◽  
Alzheimer Demenz

ZusammenfassungDie Rolle der Mikroglia innerhalb der Pathophysiologie der Alzheimer-Demenz wurde deutlich unterschätzt. Das wird durch zahlreiche In-vitro- und In-vivo-Befunde belegt. Maßgebliche neue Impulse hat dieses Forschungsfeld besonders von neueren methodischen Entwicklungen, wie der Multiphoton- in-vivo-Bildgebung und Fortschritten in neuronal-mikroglialen Modellen der Cokultur erhalten. Gleichzeitig zeichnet sich ab, dass die Mikroglia eher entscheidend die Dynamik der Krankheitsprogression steuert, als dass sie primär ätiopathogenetische Bedeutung hat. Dabei zeichnet sich zunehmend ab, dass der komplexe Beitrag der Mikroglia eher einer umgekehrten U-Funktion entspricht, wie bereits für Zytokine gut belegt: Unterfunktion mit reduzierter „Clearance” von aggregierten beta-Amyloidpeptiden und verminderter Synthese neurotropher Faktoren könnte vergleichbar schädlich sein wie Überstimulation mit erhöhter Freisetzung pro-inflammatorischer Zytokine, endoplasmatischer Stressfaktoren und reaktiver Sauerstoffradikale. Mit Blick auf potenzielle therapeutische Ansatzpunkte erscheint die pharmakologische Modulation mikroglialer Rezeptoren, wie FcgammaRIIb, Scara-1, CD33, CD36, RAGE, BECLIN- 1 und TREM2, sowie der NLRP-3-abhängigen inflammatorischen Signalkaskade besonders erfolgversprechend. In diesem Zusammenhang zeichnen sich auch attraktive Kombinationstherapien ab, einerseits in der Modulation synergistisch wirkender mikroglialer Rezeptoren, andererseits in der Kombination mit den bisher eher enttäuschenden beta-Amyloid- Immunisierungsstrategien. Im Zusammenhang mit Befunden zur altersabhängig eingeschränkten protektiven Funktion residenter Mikroglia bei AD (microglial senescence) wird auch der Einsatz von Strategien der Knochenmarktransplantation mit Invasion knochenmarkstämmiger Mikrogliazellen (BMDM, bone marrow-derived microglia) in das ZNS diskutiert. Diese Therapieansätze sind zurzeit voraussichtlich therapeutisch weniger gut steuerbar und bei Alzheimerdemenz deutlich weiter von ersten klinischen Studien entfernt.

Bone Marrow Niches for Skeletal Progenitor Cells and their Inhabitants in Health and Disease

2019 ◽  
Vol 14 (4) ◽  
pp. 305-319 ◽  
Author(s):  
Marietta Herrmann ◽  
Franz Jakob
Keyword(s):  
Bone Marrow ◽  
Progenitor Cells ◽  
Progenitor Cell ◽  
Adult Stem Cells ◽  
Current Knowledge ◽  
Cell Populations ◽  
Surface Markers ◽  
Bone Marrow Niches

The bone marrow hosts skeletal progenitor cells which have most widely been referred to as Mesenchymal Stem or Stromal Cells (MSCs), a heterogeneous population of adult stem cells possessing the potential for self-renewal and multilineage differentiation. A consensus agreement on minimal criteria has been suggested to define MSCs in vitro, including adhesion to plastic, expression of typical surface markers and the ability to differentiate towards the adipogenic, osteogenic and chondrogenic lineages but they are critically discussed since the differentiation capability of cells could not always be confirmed by stringent assays in vivo. However, these in vitro characteristics have led to the notion that progenitor cell populations, similar to MSCs in bone marrow, reside in various tissues. MSCs are in the focus of numerous (pre)clinical studies on tissue regeneration and repair.Recent advances in terms of genetic animal models enabled a couple of studies targeting skeletal progenitor cells in vivo. Accordingly, different skeletal progenitor cell populations could be identified by the expression of surface markers including nestin and leptin receptor. While there are still issues with the identity of, and the overlap between different cell populations, these studies suggested that specific microenvironments, referred to as niches, host and maintain skeletal progenitor cells in the bone marrow. Dynamic mutual interactions through biological and physical cues between niche constituting cells and niche inhabitants control dormancy, symmetric and asymmetric cell division and lineage commitment. Niche constituting cells, inhabitant cells and their extracellular matrix are subject to influences of aging and disease e.g. via cellular modulators. Protective niches can be hijacked and abused by metastasizing tumor cells, and may even be adapted via mutual education. Here, we summarize the current knowledge on bone marrow skeletal progenitor cell niches in physiology and pathophysiology. We discuss the plasticity and dynamics of bone marrow niches as well as future perspectives of targeting niches for therapeutic strategies.

scholarly journals Experimental Type 2 Diabetes Differently Impacts on the Select Functions of Bone Marrow-Derived Multipotent Stromal Cells

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 268
Author(s):  
Jonathan Ribot ◽  
Cyprien Denoeud ◽  
Guilhem Frescaline ◽  
Rebecca Landon ◽  
Hervé Petite ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Bone Marrow ◽  
Stromal Cells ◽  
Adipogenic Differentiation ◽  
Therapeutic Modality ◽  
Multipotent Stromal Cells ◽  
Cell Therapies

Bone marrow-derived multipotent stromal cells (BMMSCs) represent an attractive therapeutic modality for cell therapy in type 2 diabetes mellitus (T2DM)-associated complications. T2DM changes the bone marrow environment; however, its effects on BMMSC properties remain unclear. The present study aimed at investigating select functions and differentiation of BMMSCs harvested from the T2DM microenvironment as potential candidates for regenerative medicine. BMMSCs were obtained from Zucker diabetic fatty (ZDF; an obese-T2DM model) rats and their lean littermates (ZL; controls), and cultured under normoglycemic conditions. The BMMSCs derived from ZDF animals were fewer in number, with limited clonogenicity (by 2-fold), adhesion (by 2.9-fold), proliferation (by 50%), migration capability (by 25%), and increased apoptosis rate (by 2.5-fold) compared to their ZL counterparts. Compared to the cultured ZL-BMMSCs, the ZDF-BMMSCs exhibited (i) enhanced adipogenic differentiation (increased number of lipid droplets by 2-fold; upregulation of the Pparg, AdipoQ, and Fabp genes), possibly due to having been primed to undergo such differentiation in vivo prior to cell isolation, and (ii) different angiogenesis-related gene expression in vitro and decreased proangiogenic potential after transplantation in nude mice. These results provided evidence that the T2DM environment impairs BMMSC expansion and select functions pertinent to their efficacy when used in autologous cell therapies.

scholarly journals Comparative analysis of mouse bone marrow and adipose tissue mesenchymal stem cells for critical limb ischemia cell therapy

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Pegah Nammian ◽  
Seyedeh-Leili Asadi-Yousefabad ◽  
Sajad Daneshi ◽  
Mohammad Hasan Sheikhha ◽  
Seyed Mohammad Bagher Tabei ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Adipose Tissue ◽  
Cell Therapy ◽  
Femoral Artery ◽  
Critical Limb Ischemia ◽  
Limb Ischemia

Abstract Introduction Critical limb ischemia (CLI) is the most advanced form of peripheral arterial disease (PAD) characterized by ischemic rest pain and non-healing ulcers. Currently, the standard therapy for CLI is the surgical reconstruction and endovascular therapy or limb amputation for patients with no treatment options. Neovasculogenesis induced by mesenchymal stem cells (MSCs) therapy is a promising approach to improve CLI. Owing to their angiogenic and immunomodulatory potential, MSCs are perfect candidates for the treatment of CLI. The purpose of this study was to determine and compare the in vitro and in vivo effects of allogeneic bone marrow mesenchymal stem cells (BM-MSCs) and adipose tissue mesenchymal stem cells (AT-MSCs) on CLI treatment. Methods For the first step, BM-MSCs and AT-MSCs were isolated and characterized for the characteristic MSC phenotypes. Then, femoral artery ligation and total excision of the femoral artery were performed on C57BL/6 mice to create a CLI model. The cells were evaluated for their in vitro and in vivo biological characteristics for CLI cell therapy. In order to determine these characteristics, the following tests were performed: morphology, flow cytometry, differentiation to osteocyte and adipocyte, wound healing assay, and behavioral tests including Tarlov, Ischemia, Modified ischemia, Function and the grade of limb necrosis scores, donor cell survival assay, and histological analysis. Results Our cellular and functional tests indicated that during 28 days after cell transplantation, BM-MSCs had a great effect on endothelial cell migration, muscle restructure, functional improvements, and neovascularization in ischemic tissues compared with AT-MSCs and control groups. Conclusions Allogeneic BM-MSC transplantation resulted in a more effective recovery from critical limb ischemia compared to AT-MSCs transplantation. In fact, BM-MSC transplantation could be considered as a promising therapy for diseases with insufficient angiogenesis including hindlimb ischemia.

scholarly journals Primitive Human Hematopoietic Cells Are Enriched in Cord Blood Compared With Adult Bone Marrow or Mobilized Peripheral Blood as Measured by the Quantitative In Vivo SCID-Repopulating Cell Assay

Blood ◽  
1997 ◽  
Vol 89 (11) ◽  
pp. 3919-3924 ◽  
Author(s):  
Jean C.Y. Wang ◽  
Monica Doedens ◽  
John E. Dick
Keyword(s):  
Bone Marrow ◽  
Cord Blood ◽  
Peripheral Blood ◽  
Hematopoietic Cells ◽  
Allogeneic Transplantation ◽  
Functional Assay ◽  
Hematopoietic Stem ◽  
Mobilized Peripheral Blood

Abstract We have previously reported the development of in vivo functional assays for primitive human hematopoietic cells based on their ability to repopulate the bone marrow (BM) of severe combined immunodeficient (SCID) and nonobese diabetic/SCID (NOD/SCID) mice following intravenous transplantation. Accumulated data from gene marking and cell purification experiments indicate that the engrafting cells (defined as SCID-repopulating cells or SRC) are biologically distinct from and more primitive than most cells that can be assayed in vitro. Here we demonstrate through limiting dilution analysis that the NOD/SCID xenotransplant model provides a quantitative assay for SRC. Using this assay, the frequency of SRC in cord blood (CB) was found to be 1 in 9.3 × 105 cells. This was significantly higher than the frequency of 1 SRC in 3.0 × 106 adult BM cells or 1 in 6.0 × 106 mobilized peripheral blood (PB) cells from normal donors. Mice transplanted with limiting numbers of SRC were engrafted with both lymphoid and multilineage myeloid human cells. This functional assay is currently the only available method for quantitative analysis of human hematopoietic cells with repopulating capacity. Both CB and mobilized PB are increasingly being used as alternative sources of hematopoietic stem cells in allogeneic transplantation. Thus, the findings reported here will have important clinical as well as biologic implications.

Thrombopoietin-Induced Stimulation of Megakaryocyte- Enriched Bone Marrow Cultures

1979 ◽  
Author(s):  
K. L. Kellar ◽  
B. L. Evatt ◽  
C. R. McGrath ◽  
R. B. Ramsey
Keyword(s):  
Bone Marrow ◽  
Dna Synthesis ◽  
Bone Marrow Cells ◽  
Rabbit Plasma ◽  
Bone Marrow Cultures ◽  
Plasma Fractions ◽  
Marrow Cultures ◽  
Stimulation Of

Liquid cultures of bone marrow cells enriched for megakaryocytes were assayed for incorporation of 3H-thymidine (3H-TdR) into acid-precipitable cell digests to determine the effect of thrombopoietin on DNA synthesis. As previously described, thrombopoietin was prepared by ammonium sulfate fractionation of pooled plasma obtained from thrombocytopenic rabbits. A control fraction was prepared from normal rabbit plasma. The thrombopoietic activity of these fractions was determined in vivo with normal rabbits as assay animals and the rate of incorporation of 75Se-selenomethionine into newly formed platelets as an index of thrombopoietic activity of the infused material. Guinea pig megakaryocytes were purified using bovine serum albumin gradients. Bone marrow cultures containing 1.5-3.0x104 cells and 31%-71% megakaryocytes were incubated 18 h in modified Dulbecco’s MEM containing 10% of the concentrated plasma fractions from either thrombocytopenic or normal rabbits. In other control cultures, 0.9% NaCl was substituted for the plasma fractions. 3H-TdR incorporation was measured after cells were incubated for 3 h with 1 μCi/ml. The protein fraction containing thrombopoietin-stimulating activity caused a 25%-31% increase in 3H-TdR incorporation over that in cultures which were incubated with the similar fraction from normal plasma and a 29% increase over the activity in control cultures to which 0.9% NaCl had been added. These data suggest that thrombopoietin stimulates DNA synthesis in megakaryocytes and that this tecnique may be useful in assaying thrombopoietin in vitro.

scholarly journals Exosome-transported circRNA_0001236 enhances chondrogenesis and suppress cartilage degradation via the miR-3677-3p/Sox9 axis

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Guping Mao ◽  
Yiyang Xu ◽  
Dianbo Long ◽  
Hong Sun ◽  
Hongyi Li ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Mouse Model ◽  
Chondrogenic Differentiation ◽  
Cartilage Degradation ◽  
Human Bone ◽  
Human Bone Marrow ◽  
Luciferase Reporter ◽  
Gene And Protein Expression

Abstract Objectives Aberrations in exosomal circular RNA (circRNA) expression have been identified in various human diseases. In this study, we investigated whether exosomal circRNAs could act as competing endogenous RNAs (ceRNAs) to regulate the pathological process of osteoarthritis (OA). This study aimed to elucidate the specific MSC-derived exosomal circRNAs responsible for MSC-mediated chondrogenic differentiation using human bone marrow-derived MSCs (hMSCs) and a destabilization of the medial meniscus (DMM) mouse model of OA. Methods Exosomal circRNA deep sequencing was performed to evaluate the expression of circRNAs in human bone marrow-derived MSCs (hMSCs) induced to undergo chondrogenesis from day 0 to day 21. The regulatory and functional roles of exosomal circRNA_0001236 were examined on day 21 after inducing chondrogenesis in hMSCs and were validated in vitro and in vivo. The downstream target of circRNA_0001236 was also explored in vitro and in vivo using bioinformatics analyses. A luciferase reporter assay was used to evaluate the interaction between circRNA_0001236 and miR-3677-3p as well as the target gene sex-determining region Y-box 9 (Sox9). The function and mechanism of exosomal circRNA_0001236 in OA were explored in the DMM mouse model. Results Upregulation of exosomal circRNA_0001236 enhanced the expression of Col2a1 and Sox9 but inhibited that of MMP13 in hMSCs induced to undergo chondrogenesis. Moreover, circRNA_0001236 acted as an miR-3677-3p sponge and functioned in human chondrocytes via targeting miR-3677-3p and Sox9. Intra-articular injection of exosomal circRNA_0001236 attenuated OA in the DMM mouse model. Conclusions Our results reveal an important role for a novel exosomal circRNA_0001236 in chondrogenic differentiation. Overexpression of exosomal circRNA_0001236 promoted cartilage-specific gene and protein expression through the miR-3677-3p/Sox9 axis. Thus, circRNA_0001236-overexpressing exosomes may alleviate cartilage degradation, suppressing OA progression and enhancing cartilage repair. Our findings provide a potentially effective therapeutic strategy for treating OA.

scholarly journals MATURATION OF HEMOLYSIN-PRODUCING CELL CLONES

1970 ◽  
Vol 131 (6) ◽  
pp. 1261-1270 ◽  
Author(s):  
George C. Saunders ◽  
Douglas Swartzendruber
Keyword(s):  
Bone Marrow ◽  
Doubling Time ◽  
Sheep Erythrocyte ◽  
Mature Animal ◽  
Cell Clones ◽  
Initial Appearance ◽  
Vitro Data ◽  
In Vitro Data

Cells capable of reacting with sheep erythrocyte (SRBC) antigen to maturate and produce hemolysin appear simultaneously in the bone marrow and spleen of 1-day old Swiss-Webster mice. However, hemolysin-producing cell clones (HPCC) do not result. Complete functional precursor units generally appear in the spleens of mice older than 3 days. In vivo and in vitro data correlate well in this regard. Complete precursor units are not seen in the bone marrow and only very rarely in the thymus. The efficiency of precursor units of neonatal mice when they become functional approximates that of the mature animal when based on the doubling time of plaque-forming cells (PFC). Possible explanations of the initial appearance of incomplete precursor units have been discussed.

Atelocollagen Sponge as a Stem Cell Implantation Scaffold for the Treatment of Scarred Vocal Folds

2010 ◽  
Vol 119 (11) ◽  
pp. 805-810 ◽  
Author(s):  
Satoshi Ohno ◽  
Shigeru Hirano ◽  
Ichiro Tateya ◽  
Shin-Ichi Kanemaru ◽  
Hiroo Umeda ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Stem Cell ◽  
Stromal Cells ◽  
Fluorescent Protein ◽  
In Vitro Study ◽  
Vocal Folds ◽  
Green Fluorescent ◽  
Cell Implantation

Objectives: Treatment of vocal fold scarring remains a therapeutic challenge. Our group previously reported the efficacy of treating injured vocal folds by implantation of bone marrow—derived stromal cells containing mesenchymal stem cells. Appropriate scaffolding is necessary for the stem cell implant to achieve optimal results. Terudermis is an atelocollagen sponge derived from calf dermis. It has large pores that permit cellular entry and is degraded in vivo. These characteristics suggest that this material may be a good candidate for use as scaffolding for implantation of cells. The present in vitro study investigated the feasibility of using Terudermis as such a scaffold. Methods: Bone marrow—derived stromal cells were obtained from GFP (green fluorescent protein) mouse femurs. The cells were seeded into Terudermis and incubated for 5 days. Their survival, proliferation, and expression of extracellular matrix were examined. Results: Bone marrow—derived stromal cells adhered to Terudermis and underwent significant proliferation. Immunohistochemical examination demonstrated that adherent cells were positive for expression of vimentin, desmin, fibronectin, and fsp1 and negative for beta III tubulin. These findings indicate that these cells were mesodermal cells and attached to the atelocollagen fibers biologically. Conclusions: The data suggest that Terudermis may have potential as stem cell implantation scaffolding for the treatment of scarred vocal folds.

scholarly journals Evaluation of Browning Agents on the White Adipogenesis of Bone Marrow Mesenchymal Stromal Cells: A Contribution to Fighting Obesity

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 403
Author(s):  
Girolamo Di Maio ◽  
Nicola Alessio ◽  
Ibrahim Halil Demirsoy ◽  
Gianfranco Peluso ◽  
Silverio Perrotta ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Mesenchymal Stromal Cells ◽  
Stromal Cells ◽  
White Adipocyte ◽  
Drug Candidates ◽  
Fat Depots ◽  
Treatment Of Obesity ◽  
White Fat

Brown-like adipocytes can be induced in white fat depots by a different environmental or drug stimuli, known as “browning” or “beiging”. These brite adipocytes express thermogenin UCP1 protein and show different metabolic advantages, such as the ability to acquire a thermogenic phenotype corresponding to standard brown adipocytes that counteracts obesity. In this research, we evaluated the effects of several browning agents during white adipocyte differentiation of bone marrow-derived mesenchymal stromal cells (MSCs). Our in vitro findings identified two compounds that may warrant further in vivo investigation as possible anti-obesity drugs. We found that rosiglitazone and sildenafil are the most promising drug candidates for a browning treatment of obesity. These drugs are already available on the market for treating diabetes and erectile dysfunction, respectively. Thus, their off-label use may be contemplated, but it must be emphasized that some severe side effects are associated with use of these drugs.

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