Use of Human Perivascular Stem Cells for Bone Regeneration

Human perivascular stem cells (PSCs) can be isolated in sufficient numbers from multiple tissues for purposes of skeletal tissue engineering1-3. PSCs are ...

UCLA

Bone morphogenetic proteins (BMPs) are currently approved for spinal fusion, tibial fracture repair, and maxillofacial bone regeneration. However, BMP pleiotropism, paradoxical activities on precursor cells, and unexpected side effects at local and ectopic sites may limit their usage. Thus, the need remains for alternative osteoinductive factors that provide more bone-specific activities with fewer adverse effects. Nell-1 [Nel-like molecule-1; Nel (a protein highly expressed in neural tissue encoding epidermal growth factor like domain)] is a novel osteogenic protein believed to specifically target cells committed to the osteogenic lineage. The objective of this project is to incorporate Nell-1 into a moldable putty carrier that can adapt to bony defects and deliver Nell-1 to the local microenvironment. We show here that moldability can be achieved by mixing hyaluronan hydrogel with two types of particles: demineralized bone powder for osteoconductivity, and biomimetic apatite-coated alginate/chitosan microparticles for controlled Nell-1 delivery. Besides enhancing overall osteoconductivity of the carrier, the biomimetic apatite coating also provides a more sustained release (approximately 15% cumulative release over 30 days) and greatly reduces the initial burst release that is observed with non-coated alginate/chitosan microparticles (approximately 40% release after 1 day). The efficacy of Nell-1 delivery from these carriers was evaluated in a rat spinal fusion model against Nell-free carriers as controls. At 4 weeks post-implantation, Nell-1 enhanced spinal fusion rates as assessed by manual palpation, radiographs, high-resolution micro-computerized tomography (microCT), and histology. This moldable putty carrier system appears to be a suitable carrier for promoting osteogenesis, and will be further evaluated in larger animal models over longer periods to follow the remodeling of the regenerated bone.

Biomimetic apatite-coated alginate/chitosan microparticles as osteogenic protein carriers.

Nell-1 (Nel-like molecule-1; Nel: protein strongly expressed in neural tissue containing epidermal growth factor-like domain) is a promising osteoblast-specific growth factor for osteoinductive therapies that may circumvent adverse effects, such as nonspecific function and ectopic bone formation, associated with more established osteogenic growth factors such as bone morphogenetic proteins. Beta-tricalcium phosphate (beta-TCP), an osteoconductive, biodegradable ceramic biomaterial, has been used successfully to deliver osteoinducers for bone regeneration. The aim of this study was to develop a carrier system for efficiently delivering biologically active Nell-1 protein. After a 40% initial burst release, beta-TCP particles retained the majority of adsorbed Nell-1 protein in vitro. To test this system in vivo, L4/L5 spinal fusion was performed in three groups of rats (n = 8 each): (1) 5 microg Nell-1 in beta-TCP/demineralized bone matrix putty (DBX); (2) 2.5 microg Nell-1 in beta-TCP/DBX; (3) beta-TCP/DBX only. Fusion was assessed by radiography, palpation, microcomputed tomography, and histological analysis. After 4 weeks, 75% of Nell-1-treated animals exhibited fusion, with a significant increase in new bone volume, whereas only 25% of Nell-free control animals exhibited fusion. Our findings suggest that beta-TCP/DBX can increase both the biochemical stability and biological efficiency of Nell-1 protein.

Delivery of lyophilized Nell-1 in a rat spinal fusion model.

Healing of contaminated/infected bone defects is a significant clinical challenge. Prevalence of multi-antibiotic resistant organisms has renewed interest in the use of antiseptic silver as an effective, but less toxic antimicrobial with decreased potential for bacterial resistance. In this study, we demonstrated that metallic nanosilver particles (with a size of 20-40nm)-poly(lactic-co-glycolic acid) (PLGA) composite grafts have strong antibacterial properties. In addition, nanosilver particles-PLGA composite grafts did not inhibit adherence, proliferation, alkaline phosphatase activity, or mineralization of ongrowth MC3T3-E1 pre-osteoblasts compared to PLGA controls. Furthermore, nanosilver particles did not affect the osteoinductivity of bone morphogenetic protein 2 (BMP-2). Infected femoral defects implanted with BMP-2 coupled 2.0% nanosilver particles-PLGA composite grafts healed in 12 weeks without evidence of residual bacteria. In contrast, BMP-2 coupled PLGA control grafts failed to heal in the presence of continued bacterial colonies. Our results indicate that nanosilver of defined particle size is bactericidal without discernable in vitro and in vivo cytotoxicity or negative effects on BMP-2 osteoinductivity, making it an ideal antimicrobial for bone regeneration in infected wounds.

The use of BMP-2 coupled - Nanosilver-PLGA composite grafts to induce bone repair in grossly infected segmental defects.

Bone morphogenetic proteins (BMPs) are widely used as bone graft substitutes in spinal fusion, but are associated with numerous adverse effects. The growth factor Nel-like molecule-1 (Nell-1) is mechanistically distinct from BMPs and can minimize complications associated with BMP therapies. This study evaluates the efficacy of Nell-1 combined with demineralized bone matrix (DBM) as a novel bone graft material for interbody spine fusion using sheep, a phylogenetically advanced animal with biomechanical similarities to human spine. Nell-1+sheep DBM or Nell-1+heat-inactivated DBM (inDBM) (to determine the osteogenic effect of residual growth factors in DBM) were implanted in surgical sites as follows: (1) DBM only (control) (n=8); (2) DBM+0.3 mg/mL Nell-1 (n=8); (3) DBM+0.6 mg/mL Nell-1 (n=8); (4) inDBM only (control) (n=4); (5) inDBM+0.3 mg/mL Nell-1 (n=4); (6) inDBM+0.6 mg/mL Nell-1 (n=4). Fusion was assessed by computed tomography, microcomputed tomography, and histology. One hundred percent fusion was achieved by 3 months in the DBM+0.6 mg/mL Nell-1 group and by 4 months in the inDBM+0.6 mg/mL Nell-1 group; bone volume and mineral density were increased by 58% and 47%, respectively. These fusion rates are comparable to published reports on BMP-2 or autograft bone efficacy in sheep. Nell-1 is an independently potent osteogenic molecule that is efficacious and easily applied when combined with DBM.

Nell-1 protein promotes bone formation in a sheep spinal fusion model.

The major Food and Drug Association-approved osteoinductive factors in wide clinical use are bone morphogenetic proteins (BMPs). Although BMPs can promote robust bone formation, they also induce adverse clinical effects, including cyst-like bone formation and significant soft tissue swelling. In this study, we evaluated multiple BMP2 doses in a rat femoral segmental defect model and in a minimally traumatic rat femoral onlay model to determine its dose-dependent effects. Results of our femoral segmental defect model established a low BMP2 concentration range (5 and 10 μg/mL, total dose 0.375 and 0.75 μg in 75 μg total volume) unable to induce defect fusion, a mid-range BMP2 concentration range able to fuse the defect without adverse effects (30 μg/mL, total dose 2.25 μg in 75 μg total volume), and a high BMP2 concentration range (150, 300, and 600 μg/mL, total dose 11.25, 22.5, and 45 μg in 75 μg total volume) able to fuse the defect, but with formation of cyst-like bony shells filled with histologically confirmed adipose tissue. In addition, compared to control, 4 mg/mL BMP2 also induced significant tissue inflammatory infiltrates and exudates in the femoral onlay model that was accompanied by increased numbers of osteoclast-like cells at 3, 7, and 14 days. Overall, we consistently reproduced BMP2 side effects of cyst-like bone and soft tissue swelling using high BMP2 concentration approaching the typical human 1500 μg/mL.

High doses of bone morphogenetic protein 2 induce structurally abnormal bone and inflammation in vivo.

Effective regeneration of bone is critical for fracture repair and incorporation and healing of bone grafts used during orthopedic, dental, and craniofacial reconstructions. Nel-like molecule-1 (Nell-1) is a secreted protein identified from prematurely fused cranial sutures of craniosynostosis patients that has been found to specifically stimulate osteogenic cell differentiation and bone formation. To test the in vivo osteoinductive capacity of Nell-1, a critical-sized femoral segmental defect model in athymic rats was used.

Nell-1 enhances bone regeneration in a rat critical-sized femoral segmental defect model.

The search for novel sources of stem cells other than bone marrow mesenchymal stem cells (MSCs) for bone regeneration and repair has been a critical endeavor. We previously established an effective protocol to homogeneously purify human pericytes from multiple fetal and adult tissues, including adipose, bone marrow, skeletal muscle, and pancreas, and identified pericytes as a primitive origin of human MSCs. In the present study, we further characterized the osteogenic potential of purified human pericytes combined with a novel osteoinductive growth factor, Nell-1. Purified pericytes grown on either standard culture ware or human cancellous bone chip (hCBC) scaffolds exhibited robust osteogenic differentiation in vitro. Using a nude mouse muscle pouch model, pericytes formed significant new bone in vivo as compared to scaffold alone (hCBC). Moreover, Nell-1 significantly increased pericyte osteogenic differentiation, both in vitro and in vivo. Interestingly, Nell-1 significantly induced pericyte proliferation and was observed to have pro-angiogenic effects, both in vitro and in vivo. These studies suggest that pericytes are a potential new cell source for future efforts in skeletal regenerative medicine, and that Nell-1 is a candidate growth factor able to induce pericyte osteogenic differentiation.

The Nell-1 growth factor stimulates bone formation by purified human perivascular cells.

Pluripotent stem cells exist in naive and primed states, epitomized by mouse embryonic stem cells (ESCs) and the developmentally more advanced epiblast stem cells (EpiSCs; ref. 1). In the naive state of ESCs, the genome has an unusual open conformation and possesses a minimum of repressive epigenetic marks. In contrast, EpiSCs have activated the epigenetic machinery that supports differentiation towards the embryonic cell types. The transition from naive to primed pluripotency therefore represents a pivotal event in cellular differentiation. But the signals that control this fundamental differentiation step remain unclear. We show here that paracrine and autocrine Wnt signals are essential self-renewal factors for ESCs, and are required to inhibit their differentiation into EpiSCs. Moreover, we find that Wnt proteins in combination with the cytokine LIF are sufficient to support ESC self-renewal in the absence of any undefined factors, and support the derivation of new ESC lines, including ones from non-permissive mouse strains. Our results not only demonstrate that Wnt signals regulate the naive-to-primed pluripotency transition, but also identify Wnt as an essential and limiting ESC self-renewal factor.

Embryonic stem cells require Wnt proteins to prevent differentiation to epiblast stem cells.

&#xAC1C;&#xC694;: &#xB12C;-1, synostotic &#xB450;&#xAC1C;&#xACE8; &#xBD09;&#xD569;&#xC5D0;&#xC11C;&#xC758; overexpression&#xC5D0; &#xC758;&#xD574; &#xCC98;&#xC74C; &#xD655;&#xC778; &#xB41C; &#xC18C;&#xC124; osteoinductive &#xC131;&#xC7A5;&#xACFC; &#xCC28;&#xBCC4;&#xD654; &#xC694;&#xC18C; &#xC774;&#xB2E4;. Craniofacial &#xD328;&#xD134;&#xD654;&#xC5D0; &#xB12C;-1&#xC758; &#xC5ED;&#xD560;&#xC744; &#xC790;&#xC138;&#xD788; &#xC815;&#xC758; &#xD558;&#xB824;&#xBA74; &#xC6B0;&#xB9AC; &#xD2B9;&#xC9D5; ENU &#xC720;&#xB3C4; &#xB12C;-1-&#xACB0;&#xD54D; (&#xB05D;) &#xC950;&#xC758; &#xACB0;&#xD568; intramembranous &#xBAA8;&#xB450;&#xC5D0; &#xCD08;&#xC810;&#xC744; &#xB9DE;&#xCD94;&#xACE0; &#xBC0F; endochondral&#xC758; &#xB450;&#xAC1C;&#xACE8; &#xBF08;. &#xACB0;&#xACFC; calvarial cleidocraniodysplasia&#xC744; &#xB2EE;&#xC740; &#xD615;&#xC73C;&#xB85C; &#xC2E0;&#xC0DD;&#xC544; &#xB05D; &#xC0DD;&#xC950;&#xC758; calvarial &#xBF08; &#xB450;&#xAED8;&#xC640; &#xBC00;&#xB3C4;, &#xAC10;&#xC18C; &#xB418;&#xC5C8;&#xB2E4; &#xBCF4;&#xC5EC;&#xC8FC;&#xC5C8;&#xB2E4;. &#xB610;&#xD55C;, Runx2, &#xC54C;&#xCE7C;&#xB9AC; &#xC131; &#xC778;&#xC0B0; &#xAC00;&#xC218;&#xBD84;&#xD574; &#xD6A8;&#xC18C; &#xBC0F; osteocalcin &#xAC10;&#xCD95;&#xC744; &#xD3EC;&#xD568; &#xD55C; osteoblast &#xB9C8;&#xCEE4; &#xAE00;&#xB85C;&#xBC8C; &#xAC10;&#xC18C; &#xAD00;&#xCC30; &#xB418;&#xC5C8;&#xB2E4;. &#xB180;&#xB78D;&#xAC8C;&#xB3C4;, endochondral &#xBF08;&#xC758; &#xC0C1;&#xC138;&#xD55C; &#xBD84;&#xC11D; &#xBC1C;&#xC721; &#xC774;&#xC0C1;&#xB3C4; &#xBCF4;&#xC600;&#xB2E4;. &#xACB0;&#xAD6D; &#xB9C8;&#xC6B0;&#xC2A4;&#xC5D0; chondrocranium chondrocytes &#xC131;&#xC219;&#xC758; &#xB9C8;&#xCEE4; &#xD588;&#xB2E4; &#xAC10;&#xC18C; &#xD558;&#xB294; &#xBC18;&#xBA74; &#xBC18;&#xBA74; &#xCD08;&#xAE30;, &#xBC29;&#xC9C0;&#xD560; Sox9 chondrocytes &#xC704;&#xD574; &#xB18D;&#xCD95;&#xC744; &#xBCF4;&#xC600;&#xB2E4;. &#xC774;&#xB7EC;&#xD55C; &#xB370;&#xC774;&#xD130;&#xB294; calvarium&#xC5D0;&#xC11C; runx2&#xACFC; Sox9 &#xC2DD; &#xC870;&#xC808; &#xD558; &#xC5EC; &#xB12C;-1 osteochondral &#xCC28;&#xBCC4;&#xD654;&#xC758; &#xADDC;&#xC81C;&#xC5D0; &#xB300; &#xD55C; &#xC911;&#xC694; &#xD55C; &#xC131;&#xC7A5; &#xC778;&#xC790;&#xB294; &#xAC83;&#xC774; &#xC88B;&#xC2B5;&#xB2C8;&#xB2E4;. &#xC694;&#xC57D; &#xD558;&#xC790;&#xBA74;, &#xB12C;-1&#xC740; &#xC815;&#xC0C1; craniofacial &#xB9C9; &#xBC0F; endochondral &#xACE8;&#xACA9; &#xAC1C;&#xBC1C;&#xC5D0; &#xD544;&#xC694;&#xD55C;.

&#xB12C; 1 &#xACB0;&#xD54D; ENU &#xC720;&#xBC1C;&#xACFC; calvarial Cleidocraniodysplasia &#xAC19;&#xC740; &#xACB0;&#xD568;.

&#x6458;&#x8981;&#xFF1A; &#x5185;&#x5C14;-1&#xFF0C;&#x9996;&#x5148;&#x786E;&#x5B9A;&#x4E86;&#x7531; synostotic &#x9885;&#x7F1D;&#x7EBF;&#xFF0C;&#x53CA;&#x5176;&#x9AD8;&#x6548;&#x8868;&#x8FBE;&#x662F;&#x4E00;&#x4E2A;&#x65B0;&#x578B;&#x9AA8;&#x4FEE;&#x590D;&#x7EC6;&#x80DE;&#x751F;&#x957F;&#x548C;&#x5206;&#x5316;&#x7684;&#x56E0;&#x7D20;&#x3002;&#x8981;&#x8FDB;&#x4E00;&#x6B65;&#x5B9A;&#x4E49;&#x5185;&#x5C14; 1 &#x4F5C;&#x7528;&#x5728;&#x9885;&#x9762;&#x9635;&#x5217;&#xFF0C;&#x6211;&#x4EEC;&#x7279;&#x70B9;&#x7F3A;&#x9677; ENU &#x8BF1;&#x5BFC;&#x5185;&#x5C14;-1-&#x7F3A;&#x9677; (&#x5B8C;) &#x5C0F;&#x9F20;&#xFF0C;&#x91CD;&#x70B9;&#x653E;&#x5728;&#x4E24;&#x4E2A; intramembranous &#x548C;&#x8F6F;&#x9AA8;&#x7684;&#x5934;&#x9885;&#x9AA8;&#x5934;&#x3002;&#x7ED3;&#x679C;&#x8868;&#x660E;&#x65B0;&#x751F;&#x7ED3;&#x675F;&#x5C0F;&#x9F20;&#x9885;&#x9AA8;&#x9AA8;&#x88AB;&#x51CF;&#x5C11;&#x7684;&#x539A;&#x5EA6;&#x548C;&#x5BC6;&#x5EA6;&#xFF0C;&#x7C7B;&#x4F3C;&#x4E8E;&#x9885;&#x9AA8; cleidocraniodysplasia &#x8868;&#x578B;&#x3002;&#x6B64;&#x5916;&#xFF0C;&#x6709;&#x4EBA;&#x6307;&#x51FA;&#x9AA8;&#x5168;&#x7403;&#x51CF;&#x5C11;&#xFF0C;&#x5305;&#x62EC;&#x524A;&#x51CF; Runx2&#x3001; &#x78B1;&#x6027;&#x78F7;&#x9178;&#x9176;&#x548C;&#x9AA8;&#x9499;&#x7D20;&#x3002;&#x5F15;&#x4EBA;&#x6CE8;&#x76EE;&#x7684;&#x662F;&#xFF0C;&#x8F6F;&#x9AA8;&#x9AA8;&#x9ABC;&#x8BE6;&#x7EC6;&#x7684;&#x5206;&#x6790;&#x663E;&#x793A;&#x4EE5;&#x53CA;&#x53D1;&#x80B2;&#x4E0D;&#x826F;&#x3002;&#x4E2D;&#x7AEF;&#x9F20;&#x6807; chondrocranium &#x663E;&#x793A;&#x6D53;&#x7F29;&#x4E3A;&#x65E9;&#x671F;&#x3001; &#x589E;&#x6B96;&#x7EC6;&#x80DE;&#x6838; Sox9 &#x8F6F;&#x9AA8;&#x7EC6;&#x80DE;&#xFF0C;&#x800C;&#x76F8;&#x6BD4;&#x4E4B;&#x4E0B;&#x7684;&#x8F6F;&#x9AA8;&#x7EC6;&#x80DE;&#x6210;&#x719F;&#x6807;&#x5FD7;&#x7269;&#x51CF;&#x5C11;&#x4E86;&#x3002;&#x8FD9;&#x4E9B;&#x6570;&#x636E;&#x8868;&#x660E;&#x5185;&#x5C14; 1 &#x901A;&#x8FC7;&#x8C03;&#x8282; Runx2 &#x548C; Sox9 &#x8868;&#x8FBE;&#x5728;&#x9885;&#x5185;&#x7684;&#x8F6F;&#x9AA8;&#x5206;&#x5316;&#x8C03;&#x63A7;&#x7684;&#x4E00;&#x4E2A;&#x91CD;&#x8981;&#x589E;&#x957F;&#x56E0;&#x7D20;&#x3002;&#x603B;&#x4E4B;&#x5185;, &#x5C14;-1 &#x662F;&#x4E3A;&#x6B63;&#x5E38;&#x9885;&#x9762;&#x819C;&#x548C;&#x8F6F;&#x9AA8;&#x9AA8;&#x9ABC;&#x53D1;&#x80B2;&#x6240;&#x9700;&#x3002;

ENU &#x8BF1;&#x5BFC;&#x8010;&#x5C14; 1 &#x865A;&#x7684;&#x9885;&#x9AA8;&#x7C7B;&#x4F3C; Cleidocraniodysplasia &#x7684;&#x7F3A;&#x9677;&#x3002;

ABSTRACT: Nell-1, first identified by its overexpression in synostotic cranial sutures, is a novel osteoinductive growth and differentiation factor. To further define Nell-1's role in craniofacial patterning, we characterized defects of the ENU-induced Nell-1-deficient (END) mice, focusing on both intramembranous and endochondral cranial bones. Results showed that calvarial bones of neonatal END mice were reduced in thickness and density, with a phenotype resembling calvarial cleidocraniodysplasia. In addition, a global reduction in osteoblast markers was observed, including reductions in Runx2, alkaline phosphatase, and osteocalcin. Remarkably, detailed analysis of endochondral bones showed dysplasia as well. The chondrocranium in the END mouse showed enrichment for early, proliferating Sox9 chondrocytes, whereas in contrast markers of chondrocytes maturation were reduced. These data suggest that Nell-1 is an important growth factor for regulation of osteochondral differentiation, by regulating both Runx2 and Sox9 expression within the calvarium. In summary, Nell-1 is required for normal craniofacial membranous and endochondral skeletal development.

Calvarial Cleidocraniodysplasia-Like Defects With ENU-Induced Nell-1 Deficiency.

R&eacute;sum&eacute; : Nell-1, tout d&#39;abord identifi&eacute; par sa surexpression dans les sutures cr&acirc;niennes synostotique, est un facteur de croissance et la diff&eacute;renciation du roman ost&eacute;o-inducteurs. Pour mieux d&eacute;finir le r&ocirc;le de Nell-1 dans la structuration cranio-faciale, nous avons caract&eacute;ris&eacute; les d&eacute;fauts des souris induite par ENU Nell-1-deficient (fin), en se concentrant sur les deux intramembranaires et os cr&acirc;niens endochondrale. Les r&eacute;sultats montrent qu&#39;OS calvarial de souris n&eacute;onatales de fin ont &eacute;t&eacute; r&eacute;duites dans l&#39;&eacute;paisseur et la densit&eacute;, avec un ph&eacute;notype ressemblant &agrave; cleidocraniodysplasia calvarial. En outre, une r&eacute;duction globale de marqueurs d&#39;ost&eacute;oblastes a &eacute;t&eacute; observ&eacute;e, notamment une r&eacute;duction de Runx2, phosphatase alcaline et ost&eacute;ocalcine. Remarquablement, l&#39;analyse d&eacute;taill&eacute;e des os endochondral a montr&eacute; ainsi la dysplasie. La chondocr&acirc;ne chez la souris fin a montr&eacute; d&#39;enrichissement des chondrocytes de Sox9 pr&eacute;coces, prolif&eacute;ration, alors qu&#39;en revanche les marqueurs de chondrocytes maturation ont &eacute;t&eacute; r&eacute;duits. Ces donn&eacute;es sugg&egrave;rent que Nell-1 est un facteur de croissance important pour la r&eacute;gulation de la diff&eacute;renciation cartilagineuses, en r&eacute;gulant l&#39;expression Runx2 et Sox9 tant au sein de la vo&ucirc;te cr&acirc;nienne. En r&eacute;sum&eacute;, Nell-1 est n&eacute;cessaire au d&eacute;veloppement craniofacial membraneux et endochondrale squelette normal.

D&eacute;fauts de Cleidocraniodysplasia-Like substance ENU induite par la carence de Nell-1.

Zusammenfassung: Nell-1, zun&auml;chst durch seine &Uuml;berexpression in synostotische Sch&auml;deln&auml;hte, identifiziert ist ein neuartiger osteoinduktiven Wachstum und Differenzierung-Faktor. Weiter definieren Nell-1 Rolle in kraniofaziale Musterung gekennzeichnet wir M&auml;ngel der ENU-induzierten Nell-1-Mangel (Ende) M&auml;use, mit Schwerpunkt auf beiden intramembranous und Endochondral Sch&auml;delknochen. Ergebnisse zeigten, dass Sch&auml;delkalotte Knochen neonatale Ende M&auml;use in Dicke und Dichte, mit einem Ph&auml;notyp &auml;hnelt der Sch&auml;delkalotte Cleidocraniodysplasia reduziert wurden. Dar&uuml;ber hinaus wurde ein globaler R&uuml;ckgang der Osteoblasten Marker beobachtet, einschlie&szlig;lich Erm&auml;&szlig;igungen in Runx2, alkalische Phosphatase und Osteocalcin. Bemerkenswerterweise zeigte die detaillierte Analyse der Endochondral Knochen Dysplasie sowie. Das Chondrocranium in der END-Maus zeigte Bereicherung f&uuml;r fr&uuml;he, wuchernden Sox9 Chondrozyten, w&auml;hrend im Gegensatz dazu Marker der Chondrozyten Reifung reduziert wurden. Diese Daten legen nahe, dass Nell-1 ein wichtiger Wachstumsfaktor f&uuml;r die Regulierung der chondralen Differenzierung, ist durch die Regelung des Runx2 und Sox9 Ausdruck innerhalb der Calvarium. Zusammenfassend ist Nell-1 f&uuml;r normale kraniofaziale membran&ouml;se und Endochondral Skelett Entwicklung erforderlich.

Sch&auml;delkalotte Cleidocraniodysplasia-wie defekte mit deu-induzierte Nell-1-Mangel.

ABSTRACT: Nell-1, in primo luogo identificato dalla sua sovraespressione in synostotic suture craniche, &egrave; un fattore di crescita e differenziazione del romanzo osteoinduttivo. Per definire ulteriormente il ruolo di Nell-1 nel cranio-patterning, abbiamo caratterizzato difetti dei topi ENU-indotta Nell 1-deficit (fine), concentrandosi su entrambi intramembranosa ed endocondrale ossa craniche. I risultati hanno mostrato che cuoio capelluto ossa di topi fine neonatali sono stati ridotti in spessore e densit&agrave;, con un fenotipo simile a cuoio capelluto cleidocraniodysplasia. Inoltre, &egrave; stata osservata una riduzione globale dei marcatori degli osteoblasti, comprese le riduzioni in Runx2, osteocalcina e fosfatasi alcalina. Notevolmente, analisi dettagliata di endocondrale ossa ha mostrato displasia pure. Chondrocranium nel topo fine ha mostrato arricchimento per primi, proliferanti Sox9 condrociti, mentre al contrario marcatori di condrociti maturazione sono stati ridotti. Questi dati suggeriscono che Nell-1 &egrave; un importante fattore di crescita per la regolazione della differenziazione osteocondrali, regolando l&#39;espressione Runx2 sia Sox9 all&#39;interno del cranio. In sintesi, &egrave; necessaria per il normale sviluppo scheletrico cranio membranoso ed endocondrale Nell-1.

Cleidocraniodysplasia-come cuoio capelluti difetti con ENU-indotta carenza Nell-1.

&#x8981;&#x7D04;&#xFF1A; &#x30CD;&#x30EB;-1 &#x307E;&#x305A;&#x305D;&#x306E;&#x9AA8;&#x7652;&#x5408;&#x9AA8;&#x982D;&#x84CB;&#x7E2B;&#x5408;&#x306E;&#x904E;&#x5270;&#x767A;&#x73FE;&#x306B;&#x3088;&#x308B;&#x8B58;&#x5225;&#x5C0F;&#x8AAC;&#x9AA8;&#x306E;&#x6210;&#x9577;&#x304A;&#x3088;&#x3073;&#x5FAE;&#x5206;&#x306E;&#x8981;&#x56E0;&#x3067;&#x3059;&#x3002;&#x3055;&#x3089;&#x306B;&#x984E;&#x9854;&#x9762;&#x9AA8;&#x683C;&#x30D1;&#x30BF;&#x30FC;&#x30F3;&#x5F62;&#x6210;&#x306B;&#x30CD;&#x30EB; 1 &#x30ED;&#x30FC;&#x30EB;&#x3092;&#x5B9A;&#x7FA9;&#x3059;&#x308B;&#x306B;&#x306F;&#x3001;&#x6211;&#x3005; &#x6B20;&#x9665; enu &#x30CD;&#x30EB;-1-&#x6B20;&#x640D; (&#x30A8;&#x30F3;&#x30C9;) &#x30DE;&#x30A6;&#x30B9;&#x306E;&#x819C;&#x5185;&#x306E;&#x4E21;&#x65B9;&#x306B;&#x7126;&#x70B9;&#x3092;&#x5F53;&#x3066;&#x7279;&#x5FB4;&#x3068;&#x982D;&#x84CB;&#x9AA8;&#x8EDF;&#x9AA8;&#x5185;&#x3002;&#x982D;&#x84CB;&#x9AA8;&#x306E;&#x9AA8;&#x65B0;&#x751F;&#x7D42;&#x308F;&#x308A;&#x30DE;&#x30A6;&#x30B9;&#x306E;&#x539A;&#x3055;&#x3068;&#x5BC6;&#x5EA6;&#x3001;&#x982D;&#x84CB;&#x9AA8;&#x306E; cleidocraniodysplasia &#x306B;&#x4F3C;&#x305F;&#x8868;&#x73FE;&#x578B;&#x3068;&#x6E1B;&#x5C11;&#x3057;&#x305F;&#x7D50;&#x679C;&#x3092;&#x793A;&#x3057;&#x305F;&#x3002;&#x307E;&#x305F;&#x3001;Runx2, &#x30A2;&#x30EB;&#x30AB;&#x30EA;&#x30DB;&#x30B9;&#x30D5;&#x30A1;&#x30BF;&#x30FC;&#x30BC;&#x3001;&#x304A;&#x3088;&#x3073;&#x30AA;&#x30B9;&#x30C6;&#x30AA;&#x30AB;&#x30EB;&#x30B7;&#x30F3;&#x306E;&#x524A;&#x6E1B;&#x3092;&#x542B;&#x3080;&#x9AA8;&#x82BD;&#x7D30;&#x80DE;&#x30DE;&#x30FC;&#x30AB;&#x30FC;&#x306E;&#x30B0;&#x30ED;&#x30FC;&#x30D0;&#x30EB;&#x306A;&#x6E1B;&#x5C11;&#x304C;&#x89B3;&#x5BDF;&#x3055;&#x308C;&#x307E;&#x3057;&#x305F;&#x3002;&#x8457;&#x3057;&#x304F;&#x3001;&#x9AA8;&#x8EDF;&#x9AA8;&#x5185;&#x306E;&#x8A73;&#x7D30;&#x306A;&#x5206;&#x6790;&#x7570;&#x5F62;&#x6210;&#x306B;&#x3082;&#x793A;&#x3057;&#x305F;&#x3002;&#x30DE;&#x30FC;&#x30AB;&#x30FC;&#x306E;&#x8EDF;&#x9AA8;&#x7D30;&#x80DE;&#x6210;&#x719F;&#x306E;&#x5BFE;&#x7167;&#x7684;&#x306B;&#x6E1B;&#x5C11;&#x3057;&#x305F;&#x306B;&#x5BFE;&#x3057;&#x7D42;&#x308F;&#x308A;&#x30DE;&#x30A6;&#x30B9;&#x3067; chondrocranium &#x6FC3;&#x7E2E; Sox9 &#x8EDF;&#x9AA8;&#x3001;&#x65E9;&#x3044;&#x3001;&#x5897;&#x6B96;&#x3092;&#x793A;&#x3057;&#x305F;&#x3002;&#x30CD;&#x30EB; 1 Runx2 &#x3068; Sox9 &#x5F0F;&#x3001;calvarium &#x5185;&#x306E;&#x8ABF;&#x6574;&#x306B;&#x3088;&#x3063;&#x3066;&#x9AA8;&#x8EDF;&#x9AA8;&#x5206;&#x5316;&#x306E;&#x8ABF;&#x7BC0;&#x306E;&#x305F;&#x3081;&#x306E;&#x91CD;&#x8981;&#x306A;&#x6210;&#x9577;&#x306E;&#x8981;&#x56E0;&#x3067;&#x3042;&#x308B;&#x3053;&#x3068;&#x304C;&#x793A;&#x5506;&#x3055;&#x308C;&#x305F;.&#x8981;&#x7D04;&#x3059;&#x308B;&#x3068;&#x3001;&#x30CD;&#x30EB; 1 &#x306F;&#x901A;&#x5E38;&#x9854;&#x9762;&#x819C;&#x3068;&#x8EDF;&#x9AA8;&#x5185;&#x9AA8;&#x683C;&#x767A;&#x9054;&#x306B;&#x5FC5;&#x8981;&#x3067;&#x3059;&#x3002;

ENU &#x8A98;&#x767A;&#x30CD;&#x30EB; 1 &#x6B20;&#x4E4F;&#x3068;&#x982D;&#x84CB;&#x9AA8;&#x306E; Cleidocraniodysplasia &#x306E;&#x3088;&#x3046;&#x306A;&#x6B20;&#x9665;&#x3002;

Resumen: Nell-1, primera vez identificado por su sobreexpresi&oacute;n en synostotic suturas craneales, es un factor de crecimiento y diferenciaci&oacute;n de novela Osteoinductor. Para definir m&aacute;s papel de Nell-1 en modelar craneofacial, caracterizamos defectos de los ratones inducida por ENU Nell-1-deficiente (final), enfocando ambos intramembranosa y endocondral huesos craneales. Los resultados mostraron que los huesos calvarial de ratones de final neonatales fueron reducidos en espesor y densidad, con un fenotipo que se asemejan a cleidocraniodysplasia calvarial. Adem&aacute;s, se observ&oacute; una reducci&oacute;n global en los marcadores de osteoblastos, incluyendo reducciones en Runx2, fosfatasa alcalina y osteocalcina. Notable, el an&aacute;lisis detallado de los huesos endocondral demostr&oacute; displasia as&iacute;. El Condrocr&aacute;neo en el rat&oacute;n final demostr&oacute; enriquecimiento de condrocitos de Sox9 temprano, proliferaci&oacute;n, mientras que en cambio se redujeron los marcadores de maduraci&oacute;n de los condrocitos. Estos datos sugieren que Nell-1 es un importante factor de crecimiento para la regulaci&oacute;n de la diferenciaci&oacute;n osteocondral, regulando la expresi&oacute;n de Sox9 tanto Runx2 dentro de la b&oacute;veda craneal. En Resumen, Nell-1 se requiere para el normal desarrollo esquel&eacute;tico membranoso y endocondral craneofacial.

Ronald K. Siu

Department of Bioengineering

UCLA

Use of Human Perivascular Stem Cells for Bone Regeneration

Ronald K. Siu

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Department of Bioengineering

UCLA

Use of Human Perivascular Stem Cells for Bone Regeneration

Department of Bioengineering